Combi Boiler. System Drainage.

Occasionally it may be necessary to drain down a combi boiler and central heating system. This may be to facilitate maintenance procedures, cleaning the system or the addition of extra radiators.

The process is relatively simple, but prior to attempting to drain a system, it is advisable to ensure that the person carrying out the draining also knows how to re-fill, add inhibitor and pressurise the system once the work has been carried out.

The method of pressurising of a combi boiler system varies between model and manufacturer. Instructions for pressurising may be found in the boiler user’s manual.

It is important to note that if the actual boiler requires draining, this must only be carried out by a competent person. Draining a combi boiler system does not involve draining the internal part of the boiler.

Before draining the combi boiler system it is important to ensure that the mains electricity supply to the boiler and any system programmers are turned off. This is to prevent the boiler operating with an empty system, which could seriously damage the boiler.

It is not necessary to turn off the mains water supply when draining a combi boiler system.

To drain the central heating system, first, locate the drain tap. This will be on the ground floor or the lowest point of the system. Occasionally it will be conveniently located at the end of a leg of pipe leading from a radiator to the outside of the property. If not, a length of hose will need to be attached to the spigot and run to the outside of the property or to a ground level drain entrance.

With the drain tap opened, water should start to flow out of the system. This flow will need to be supported by opening up the bleed valves on all the radiators attached to the system, starting at the top of the property or the radiator furthest from the drainage tap. Air entering the system will replace the vacating central heating fluid.

With the system drained, now is a good time to flush through the central heating system to remove debris. This is best accomplished by engaging the services of a specialist company, however, some sludge and debris can be removed by operating the refilling device to allow water to flow through and out of the system. It will be necessary to close off the radiator bleed valves to facilitate the flushing through of upstairs radiators.

Once any maintenance work has been accomplished, the system can be refilled and pressurised.

Firstly, the drain tap should be closed off. It is then essential to go round all the radiators and close off the bleed valves using the radiator bleed key.

At this point, it is essential to add an inhibitor solution into the system. A good way to do this is to locate the plug at the top of one radiator. This plug will be at the opposite end to the bleed valve. Removing this screw threaded plug will reveal an opening into which the required amount of inhibitor can be added using a funnel or open-ended tube.

The correct amount of inhibitor required by the system can be calculated by using the information supplied with the inhibitor.
Do not forget to replace and firmly tighten the radiator plug after adding the inhibitor.

Water should now be allowed back into the system using the filling loop or the refilling device appropriate to the particular boiler. This may be a key type facility, which operates an internal valve system within the boiler.

As water re-enters the system, the pressure gauge on the boiler should start to register an increase in system pressure. If it does not, immediately close off the filling loop and check the entire central heating system for any leaks. It may be found that a bleed valve on a radiator has not been closed off correctly or some new work on the system is leaking.

When the pressure indicator on the boiler reads one bar, the filling loop should be turned off and all the radiators bled to remove trapped air in the system. The bleed valves on the radiators should be bled from the nearest radiator to the boiler along and up to the radiators upstairs, or the furthest from the boiler. It will be necessary to return to the boiler filling loop and re-fill the system after bleeding the air from each radiator.

With all the air removed from the system, the filling loop should be operated to pressurise the system up to the manufacturer’s recommended cold pressure operating level. This is usually between 0.5 and 1.5 bar.

Once the correct pressure is reached, the boiler power, the programmers, and the timers can be turned back on.

The boiler and central heating should now operate correctly. Any banging or loud gurgling sounds will indicate that air is still trapped within the system, as will any radiators that are hot at the base but cold at the top.

To remedy these situations, the radiators will need further bleeding to remove the trapped air.

To clean a combi boiler system, the process is similar to that described above.

First, drain down the system. Flush through with clean water. Refill with water and a suitable cleaning fluid such as Fernox. Re-pressurise the system and run for 48 hours. Drain down the system again. Flush through with clean water and refill the system with inhibitor. Finally, re-pressurise the system.

Before undertaking any DIY work on a combi boiler central heating system, it is advisable to check that the work will not invalidate any warranty on the boiler that might be in place.

DIY Plumbing and Pollution

One of the greatest eureka moments in human history was the discovery that many diseases were contracted by people drinking contaminated water supplies.

These horrible diseases plagued our early towns and cities and were compounded by the lack of sanitation and the fact that human activity created waste compounds that were not being correctly disposed of. Blood and waste products from animal slaughter, toxins and heavy metals produced by manufacturing processes and the faecal and food waste products from human habitation trickled through open street troughs and into the nearest river or watercourse. These same watercourses provided much of the drinking water the inhabitants who could not afford cheap ale were forced to drink.

Life expectancy was short and early childhood mortality was the norm.

Today, things are much different. Sewage and other foul water wastes are carefully directed along dedicated pipe networks to vast treatment plants. Here they are carefully treated to clean out most of the harmful components before they are allowed to enter streams, rivers and oceans.

Surface water from roofs and other surfaces are kept separate and, because of their relative cleanliness, directed straight into streams and other watercourses where they become diluted and rendered harmless.

All very notable and efficient. Or is it?

Unfortunately, too much material that should be sent into the sewage system for treatment is currently being wrongly directed into the surface water system. Although not entirely the cause of the problem, much of the blame is being placed at the door of over enthusiastic DIY operatives who incompetently plumb appliance’s wastewater discharge pipes into the wrong drain. Dishwashers, washing machines, baths and sinks, even toilets can inadvertently have their waste flushed into the wrong pipe.

This rise in DIY activity is believed to be one of the contributing factors. The proliferation of daytime TV DIY and house renovation programmes seems to have spurred an increase in inexperienced householders keen to save money by carrying out their own installations and home improvement work. This, coupled with the recession, which has deterred people from moving house and motivated them to alternatively embark on home improvement projects instead, has compounded the problem.

Today, the ease at which DIY appliances, fittings and other components and tools can be sourced, and the relatively cheap price of these items, has made DIY a leisure activity for many.

The recession has also meant that affording the services of qualified trades people has become increasingly beyond the financial means of many householders.

As a result, more and more effluent and other toxic substances are finding their way into the wrong drains and subsequently directly into the natural water systems.

DEFRA predicts that by 2017, over half a million properties in the UK will have misconnected and technically illegal drainage connections installed. Currently, in some areas, one in five households is known to have incorrectly plumbed drainage systems.

The damage caused to the environment is substantial. The decomposing material in rivers and seas removes oxygen from the water. This suffocates fish and encourages eutrophication, or the proliferation of algae, which forms dense blankets on water surfaces cutting out sunlight. Salmon, perch, pike and trout all succumb to this unnatural imbalance created by the disruption of normal environmental processes.

Toxic chemicals can cause undesirable mutations in wildlife. The endocrine disrupters released from contraceptive pills and flushed directly into clean watercourses can cause gender alterations in fish and other aquatic life.

However, not all problems are caused by hapless DIY operatives.

Too often toxic materials are deliberately discarded into drains, particularly street drains. Oil, antifreeze, and other motoring products are often flushed directly into them by inconsiderate vehicle owners.

The increase in the construction of external hardcover surfaces prevents natural drainage and following a rain downpour, water, and the debris collected on these surface gushes into storm drains, causing considerable pollution.

Not only is a polluted water course unattractive, the smell of decomposing organic material coupled with the myriad of unexpected chemical reactions that may occur can be quite unpleasant for neighbouring households.

So concerned are various environmental groups about this growing problem, that many are now monitoring watercourses to detect sewage contamination. Dyes can be added to pipe networks to discover the origins of contamination points.

Fly populations that inhabit waterside environments are being monitored to detect alterations in normal populations caused by trace contaminants. When detected, the Environment Agency is informed. The Agency is then obliged to carry out further investigations to try to determine the source of the problem before it becomes a serious issue.

The government has also set up the Connect Right campaign. This body provides information and advice to homeowners and developers about connecting appliances to the correct drainage system. It also provides links to accredited Water Safe plumbing engineers. These plumbers and fitters have the relevant experience and the technical understanding of environmental issues to ensure that any work is correctly undertaken.

Homeowners with older properties are also recommended to have their drainage systems regularly checked to ensure correct operation. Deterioration of older pipe-work can cause seepage of contaminants into the wider environment causing harm to wildlife and human populations alike.

For homeowners and DIY enthusiasts, taking care to ensure that drainage systems are correctly identified prior to embarking on installations will help to reduce the problems associated with incorrect connection issues.

Where any plumbing work lies beyond the scope or experience of the householder, employing a professional and competent plumber will ensure that our natural habitats remain as unaffected by human activity as is possible.

Hot Water Airlocks in Indirect Systems


Air trapped in the water supply pipework can cause homeowners considerable inconvenience, particularly when it becomes a recurrent problem. Central heating airlocks are generally easy to resolve and may simply require the bleeding of radiators.

When the air becomes trapped in the domestic hot water supply, dealing with it can become a little more complex.

The presence of low pressure at a hot water outlet may be caused by a number of problems. If the problem seems to be restricted to one outlet, it may be worth checking to see whether a filter is incorporated in the tap or device. Filters in tap fittings occasionally become blocked with limescale and other debris or mineral deposits. The filters can be removed and cleaned.

In old hot taps, damaged washers or excessive wear and tear can lead to flow problems. Older taps are better replaced with newer ones.

Internal filters in shower devices, particularly electric ones, are a specialist task and should be serviced by a competent person.

Where low hot water pressure occurs frequently, with or without air locking problems, it is important to check whether the mains supply to the water storage tank in the loft is sufficient. It might also be necessary to check the tank’s capacity to ensure it is sufficient to meet demand. Where water flows out of the tank faster than it can be replaced, the potential for air to enter the system is greatly increased.

Blockages can also occur in ball valves that restrict the flow of mains water into the tank. To check mains pressure at the ball valve, place a finger over the valve outlet and press down the ball cock. It will be impossible to prevent good mains pressure water from escaping around a finger. A blocked valve should be cleaned.

Airlocks may also occur if a storage tank runs dry when the mains water supply is interrupted, for instance due to a provider carrying out maintenance work on their system.

Where the mains supply is sufficient and yet all the hot taps are experiencing low or non-existent flow rates, an airlock in the system is the likely cause.

There are a number of ways to try to remove an airlock. If the mains water supply is delivered by a single cold-water tap at the kitchen sink, it is possible to firmly attach a length of hose from the spout of the cold tap to the spout of the hot tap. With the hot tap turned on, the cold tap should be gradually opened. Cold water at mains pressure will flow into the hot water system forcing any air through the system and back into the cold-water storage tank in the loft. The cold water should only need to flow for a few seconds to clear the pipes.

If the tap at the sink is a mixer type, it may be possible to cover the outlet spout with one hand. Then, with the other hand turn on the hot tap followed by the cold tap. Water will be forced from the cold into the hot tap completing the process outlined in the above method. A short length of hosepipe firmly attached to the spout and with both taps open can offer an alternative to using a hand. With the cold water flowing, tightly nip the hosepipe. This will force cold water into the hot water system.

On some mixer taps, non-return valves are installed internally to prevent backflow occurring. If this is the case, the above method will not work. However, an alternative method can be used. If a washing machine is installed and connected by hot and cold separate pipes, it is possible to turn off the supply valves to the hoses, disconnect them from the machine, join them together and turn on the hot, and then cold supply valves. Provided that the cold supply is at mains pressure, the cold water will force itself through the hot water system, hopefully taking the airlock with it. The supply pipes can then be reattached to the washing machine.

If these methods fail to remove the airlock, a final method is to turn off a suitable hot tap at its isolation point. This is usually a small valve located on the pipework supplying it. It is then necessary to dismantle the tap to a point where it is possible to attach a length of hosepipe. The other end must be attached securely to a cold tap supplying mains pressure. With the hot tap isolation valve open, turn on the cold supply and allow the cold water to enter the hot water system and flush out the airlock into the main storage tank. Once this is accomplished, turn off the main water tap. Close the hot tap isolation valve and reassemble the tap.

It is a good idea to have an observer stationed at the water tank in the loft with any of these methods to confirm successful operation and to warn of any danger of the tank overflowing during the process.

Repeated airlocks can sometimes be caused by air being pulled back into the system through the water expansion pipe. It is worth getting someone to go into the loft and cover the expansion vent pipe exit with their hand. At the same time have someone turn on the lowest hot tap on the circuit. This can force trapped air out of the system.

If these methods fail, it may be necessary to drain down the entire domestic hot water system.

First, ensure that the boiler and all pumps etc are turned off. Turn off the water feed to the storage tank. Then open all the hot taps to drain down the system. If any sludge is visible in the bottom of the tank, avoid allowing this material to be drawn down into the pipe-work. Sludge should be removed with a suitable scoop and bucket and the tank disconnected and cleaned correctly.

Once the system has drained, go round and close each hot tap until they are about three-quarters closed. Now turn the water supply to the storage tank back on. The tank will start to fill and eventually all the taps should have a gentle flow of water. Adjust each tap slightly so that the flow rate through each is similar. Starting with the lowest in the system, work upwards with each hot tap, turning them on further about half a turn. Return to the first tap and repeat the process again. Keep doing this until all the hot taps are fully turned on and all the air has been removed. The next step is to slowly turn them off until each tap has just a trickle. Let them run for a minute or so and then turn them all off. Do not forget to restart the boiler and any associated pumps when the task is completed. If the water pressure is particularly low, it may be necessary to fill the storage tank prior to operating the taps.

If this does not solve the problem, it is time to call in a professional to ensure that the problem does not lie elsewhere within the system.




Plumbing-In a Washing Machine or Dishwasher

With today’s easily obtainable plumbing supplies and fittings, plumbing a new washing machine or dishwasher is a relatively straightforward operation. Simple installations are well within the capabilities of any competent DIY enthusiast. Installations that are more complex may need the assistance of a general handyman or plumber to ensure that pipe fittings are correctly incorporated to allow the appliance to function reliably.

Perhaps the simplest installation is the replacement of an existing appliance with a new one. So long as the electricity plug has been removed from its socket, the water in-line supply valve turned off, the hose(s) unscrewed and the waste pipe disconnected; the old appliance can be eased from its existing position and disposed of.

In the case of a new washing machine, first, remove all packaging and either keep it in case it may be required again, or dispose of it. The main thing is to get it out of the way. Then, and with reference to the manufacturer’s installation instructions, the drum transit restraining bolts must be removed completely from the machine. These bolts prevent the drum from moving on its axle during transport. Failure to remove the bolts before operating the machine will seriously damage it. Keep these bolts safe in case it becomes necessary to transport the machine in the future.

To prevent unbalanced drum operation, the machine must be level. This can be achieved using a spirit level whilst adjusting the machine feet. The machine must also be stable and not able to rock when operating. The feet should also be adjusted to ensure that the machine will fit comfortably below any work surfaces.

Modern washing machines now have a single water connection hose. This has a fitting coloured blue and should be screwed onto the cold water supply fitting. This fitting should only be tightened by hand. The drainage and electrical fittings should all fit into the old connections with no need for modification. The new washing machine can then be slid into the existing space, taking care not to kink any of the pipes whilst doing so. The water supply can then be turned back on at the inline valve. Prior to switching on the electrical supply, it is a good idea to ensure that the operating switch on the machine is turned off otherwise the machine door will automatically lock when the power is supplied.

The manufacturer’s instructions will probably recommend running the machine empty on a hot wash prior to attempting to wash any fabrics. During the first operation, it is a wise precaution to monitor the machine and connections for any problems that might arise.

Installing a replacement dishwasher follows the same procedure; however, there are no transit bolts to remove. The machine must be level to ensure effective dish washing operation. Fittings are generally identical the previous installation.

To provide installation points for a new washing machine or dishwasher, slightly more complex plumbing procedures are required; however, it is possible to obtain all the necessary parts in a kit from major DIY outlets.

The first thing to consider is where to position the appliance. Not all appliances have to be located in the kitchen. Some homeowners prefer to locate appliances, particularly washing machines, in garages or conservatories. However, consideration must be given to frost protection.

Dishwashers tend to be located in the kitchen due to the frequency of operation and for convenience.

What both appliances require are a power source and water and waste connections. For that reason, both appliances tend to be located in the kitchen close to the sink where access to a cold water supply and drainage is readily available. In all probability, an electric socket will also be on hand to plug the appliance into.

To make a water connection to a cold pipe, first, isolate the pipe area or turn off the rising main. Drain the system as much as possible and then cut out a section of the supply pipe to accommodate a T fitting. All fittings should be either soldered or compression joints, depending on preference. An adequate length of pipe should be fitted into the T with an isolation valve to cut off the water supply in the event of a hose failure. A suitable connector should then be fixed to the end of the pipe to accommodate the machine hose. Incorporating a check valve should also be considered.

It is possible to obtain self-boring fittings that simply screw into existing pipework. These should be securely attached to a wall and in the off position prior to operating the self-tapping valve. It is also advisable to check with the water supplier that these fittings are permitted.

To fit a waste drainage connection firstly check the appliance manufacturer’s recommendations to ensure that a suitable outlet will be provided. The most common outlet consists of a vertical pipe with a minimum 40 mm diameter. This vertical pipe must have its top opening high enough to prevent any back-flow of water into the machine. This can be plumbed into the sink waste pipe with a suitable connection. The top of the pipe accommodates the machine waste pipe that simply hooks onto it. It is possible for two machine drainage pipes to be hooked onto this down pipe but it might not be advisable to have both machines draining at the same time.

Alternatively, a dedicated drainage fitting can be installed directly into the sink drainage system just above the trap. This fitting usually has two branches to accommodate two appliance drain hoses. Prior to fitting the drain hoses, blocking caps, either fitted internally or externally on each branch must be removed. In some instances, they may need to be sawn off.

To fit either appliance in a garage or alternative position, it will be necessary to provide independent water and drainage supply pipes. Although this can be straightforward if services are within easy access, providing these points may require professional intervention, particularly where new electrical installations will be required.

In general, installing a washing machine or dishwasher can be carried out without the need to employ a professional plumbing engineer.

How to Repair the Main Stopcock

The house stopcock, or shut off valve, controls the mains flow of cold potable water into the property. It is commonly located under the kitchen sink although it may also be installed near a front door, in a cupboard, or even under a floorboard. It would be uncommon to find more than one stopcock controlling the mains water supply into an individual property.

Most stopcocks have to be manually operated, although there are now some being installed that are electronically operated. Electronically controlled stopcocks require specialist maintenance and should not be serviced by the householder.

It is most important that the householders are able to locate, identify and operate the manual stopcock. This is because it is the most practical way of closing off the pressurised mains water supply into the property. This would need to be carried out quickly in the event of a water leak or burst pipe within the property. It might also need to be operated to facilitate water appliance repairs or installations.

Perhaps the biggest problem that occurs with mains water supply stopcocks is the inability to turn them off. This is due to infrequent use. Without a frequent operation, the internal mechanism becomes affected by mineral particles and substances produced by the effects of metal corrosion. These adhere to the surfaces of the moving parts. Over time, this causes the washer and jumper mechanism to seize up. The crutch head becomes very difficult, if not impossible to turn. In the panic of a plumbing emergency, it is not uncommon for a householder to apply excessive force to the crutch head of a seized stopcock. Unfortunately, this can result in the crutch head shearing off from the spindle, leaving the valve in the open position.

It is also important to ensure that the operative knows which direction of turn opens and closes the stopcock. It is not unusual to find a householder has sheared off the crutch head by applying excessive force in the wrong direction.

Anti-clockwise opens. Clockwise closes.

To prevent problems occurring with a stopcock, it is a good idea to turn it on and off regularly. This will help to prevent a build up of material and ensure that the mechanism operates freely. It is also a good idea to turn a freely operating stopcock fully on, and then give it a half turn clockwise and leave it at that position. This will provide a little extra play on the device should it become stiff to operate in the future.

To free a seized or difficult to operate stopcock, spray a little penetrating and lubricating oil onto the spindle and gland nut, and then leave it to seep into the mechanism. This should solve the problem. If that does not work, slacken the gland nut and apply the spray again. If the stopcock still refuses to operate, a small amount of force can be applied to the crutch head using a wrench.

Occasionally, applying a carefully directed blowtorch flame to the gland nut will provide just enough metal expansion to free the seized mechanism. It is a wise precaution to clean away any surplus penetrating oil before doing so.

If all attempts to free a seized stopcock fail, the water supply can be turned off at the water supplier’s main valve. This will usually be located outside the homeowner’s boundary. It may be on the pavement under a small iron cover marked SVS, or it may have the water suppliers identifying mark. Sometimes this valve is a normal stopcock, but more often than not it is a spindle headed valve that requires a specific tool to operate it. This can be obtained from tool hire firms.

Alternatively, the water supplier will attend to operate the device. This mains stopcock is the property of the water supplier and its maintenance and operation are technically their responsibility.

On some networks, turning off the water supplier’s mains water valve will affect other residents. They should be forewarned about any interruption to their supplies.

Turning off the water supplier’s mains supply valve will facilitate the repair or replacement of the domestic water stopcock. It is quite feasible for a competent DIY enthusiast to strip down and service a mains stopcock or to remove and install a new one. However, the location of the stopcock may make access and work on it difficult due to restricted working space.

When removing and replacing a domestic mains stopcock, there will be a significant amount of water and pressure remaining in the system when the supplier’s valve has been turned off. This pressure can be released by turning on the domestic cold-water tap. Unless a drain valve has been installed close to the stopcock, a suitable receptacle will be required to collect any surplus water draining from the pipe above the stopcock.

On other occasions, a householder may become aware of a slow leak from a stopcock. Left unattended, a small leak can cause substantial damage to the fabric of a property. The most usual causes are leaking compression nuts or deterioration of the gland packing material.

Leaks from the compression nuts can be addressed by gently tightening the nuts. Care should be taken to not over-tighten compression nuts, as this will interfere with the correct operation of the stopcock. The stopcock should be held firmly with a set of grips whilst tightening the compression nuts to prevent fracturing the attached pipe-work.

Leaks from the gland head can be rectified by trying to tighten the gland nut. If that fails to stop the leak, removing the crutch and unscrewing the gland will allow the householder to clean away any detritus and old packing material. It is not necessary to turn off the water supplier’s main valve to accomplish this task. PTFE tape can then be gently wound around the exposed area of the spindle and prodded down into the gland area with a screwdriver. The gland nut and spindle can then be re-attached.

In general, the regular inspection and operation of the domestic mains stopcock will ensure problems do not occur, or only become apparent in an emergency.

Because of the substantial damage that can be caused by unmanageable releases of water under mains pressure and the subsequent insurance implications, if there is any doubt over issues relating to competency, professional assistance should be sought in relation to stopcock operating issues.

Replacing a Hot Water Cylinder on a Vented System

A friend of mine has just moved into a rather splendid period property. Large and spacious, it is ideal for his rapidly expanding family. With a modern condensing boiler and a programmable zoning installation controlling the radiators throughout the house, he is confident he can keep his heating bills under control.

The previous occupants also had a large family and found an open vented hot water storage system ideal for their requirements. Where large amounts of hot water are required on-tap, storing hot water in a cylinder is a practical solution to cope with a high quantity demand.

With the property having three floors there is also a good head of pressure available from the cold water feed tank in the loft. This provides a good hot water flow and pressure rate through the cylinder and out of the taps.

However, after taking off the hot water storage cylinder insulation jacket to inspect the tank, my friend noticed that water had been leaking from the indirect heating coil flow pipe leading into the cylinder. Green and white encrustation around the external connection was quite evident along with an indication that someone had tried to stop the leak with a filler compound in the past.

Realising that the copper cylinder was quite old, my friend decided it was time to replace it, rather than try to mend the leak.

Because he has an open vented hot water system, he decided to undertake the work himself. Open vented means that when hot water is heated and expands, the surplus water volume is directed up a pipe leading to the cold water feed tank. If the expansion becomes too great within the system, surplus hot water can be discharged back into the cold water feed tank. This maintains a low and safe working pressure within the system. Any excess of water flowing back into the cold water feed tank is simply expelled from the property via the overflow pipe.

If he had inherited an unvented system, the replacement of a hot water storage cylinder would have been a specialised procedure requiring expert installation.

The original hot water storage cylinder was snugly located in an enclosed cupboard in the bathroom. Although this meant that installing a new cylinder would have to be undertaken in a rather confined space, my friend decided that this location would still be suitable. The installation would simply require the removal of the old tank and the insertion of a new one, plumbing into existing fittings.

New hot water storage cylinders are available in a variety of sizes. Smaller properties can also benefit from installing vented combination cylinders, where the cold-water feed and expansion tank is incorporated into the storage unit. This is designed to save space but can lead to problems with low hot water flow rates.

General domestic vented hot water storage cylinders come in a variety of sizes ranging from 74 litres up to 450 litres. Because the existing cylinder in my friend’s house had a 200-litre capacity, he decided to replace it, like for like, with one of the same capacity and dimensions to ensure that it would fit into the available space.

The new cylinder was coated with a highly efficient foam insulation skin and also had provision for the attachment of a backup electric immersion element in the same position as the existing cylinder. Inlet and outlet fitting locations were also chosen to be identical to try to ensure a problem free installation.

Having obtained the replacement hot water storage cylinder, my friend turned his attention to removing the old one.

Firstly, he shut down the boiler and all the other accessories, pumps, electronic diverter valves and programming installations and then, because there were no additional isolating valves, drained down the central heating system.

He then isolated the current immersion heater element electrical supply.

The existing cylinder now needed draining. This was accomplished by turning off the mains cold feed to the water feed and expansion tank and locating the drain tap, fortunately, plumbed from the rear of the storage cylinder and feeding through to the front.

Next, he disconnected the electrical contacts in the head of the electric immersion heater and then removed the external thermostat device that was secured to the wall of the cylinder.

He was then able to unscrew the cylinder attachment fittings. They were the heating coil inlet and outlet points and the hot water outlet pipe at the top of the cylinder. He was fortunate that they were easy to free and unscrew. However, he could have cut the pipes at appropriate points, ensuring that he could re-plumb when necessary. He also took the precaution of marking the pipe-work to identify which pipe corresponded to which function.

To ensure convenient re-plumbing of the cold-water inlet, in this case, located at the back of the cylinder, he cut this pipe some way above the cylinder. By doing this, he could attach fittings and a length of copper pipe to the rear of the new cylinder prior to moving it into position. This saved him having to struggle to plumb the cold feed into the base of the back of the cylinder when placed in its new location.

He enlisted my assistance to remove the old tank and carry it downstairs. We were quite surprised by the weight of the old cylinder and decided to cut the top off and examine the internal area. This was encrusted with limescale, with a thick coating covering the coils and electric heating element. The base of the cylinder had about six inches of scale and debris, almost clogging the cold water feed inlet. This indicated that the water supplying my friend’s property was particularly hard.

Attention now turned to the new replacement cylinder. To ensure a watertight fitting of a new immersion heater element, a small circular ring of foam insulation was cut from the edge of the element fitting area. The element was then screwed into position, seating perfectly into the cut area and forming a tight seal.

With fittings, and an appropriately measured length of copper pipe attached to the rear cold water inlet point, not forgetting the attachment of a new drain valve leading from the back base coupling to the front area, the new cylinder was inserted into position.

The heating coil inlet and outlet pipes and the hot water outlet pipes were re-attached. The cold-water inlet pipe extension from the back of the cylinder required coupling to the pipe from the cold-water feed and expansion tank.

To facilitate future maintenance work, gate valves were installed at suitable pipe junctions to enable the cylinder to be easily isolated from all water supplies.

The new immersion element was rewired into the mains, and a small piece of insulation foam was cut from the front of the new cylinder to allow attachment of the thermostat.

The mains water was turned back on and the entire system was refilled, not forgetting the addition of inhibitor into the central heating system. The boiler was then re-started and all contributing electrical appliances turned on.

The immersion heater was checked to ensure it was working, radiators were bled to remove airlocks and the system restored to a functioning hot water and central heating installation.

The new hot water storage cylinder and its related plumbing couplings were frequently inspected for a few weeks to ensure that no problems or leaks emerged.

With the new hot water storage cylinder installed, my friend could now relax, confident that a major cylinder failure and water leak issue was unlikely to arise.

Fitting a Magnetic Filter? DIY!

If at any time you thought that your wet central heating system was a ‘fit and forget’ feature, I am sure that now, and possibly as a result of experience, you’ll have come to a completely different opinion.

Perhaps you might have thought that you could save money by running your central heating for a a few years without regular maintenance.

Trouble is, sooner or later your system is going to start deteriorating and could eventually succumb to a rather expensive failure.

Something of a false economy.

In addition, a lack of regular attention will cost you more than inconvenience and costly breakdowns.

Running a poorly maintained system can send your heating bills sky high as the pump and boiler struggle to heat and push water through constricted, scaled pipes, sludge and sediment clogged radiators and mineral-encrusted heat exchangers.

Regardless of the type of system you’ve had installed, whether it is a sealed combi, open or a vented heating system, the most common problem you are likely to experience is that of natural corrosion of the metallic components of the system.

This can be reduced very effectively by periodically power flushing the system and by the regular use, and maintaining of, an adequate concentration of inhibitor.

However, power flushing can leave behind stubborn sediments that could eventually dislodge and become suspended in the circulating water. These particles, usually composed of metal oxides, can continue to cause damage to boiler components even in what might have been considered a cleaned system.

This, combined with a continual accumulation of debris, can increase the frequency of the need to power flush.

The answer to removing these particles lies in the introduction of a magnet into the system.

There are a number of domestic magnetic filters available, but the most popular and effective is the Magna Clean device.

The Magna Clean is a compact filter appliance of simple but ingenious construction containing a powerful internal magnet. This very effectively collects any metallic particles suspended in the water. Its small size means that it can be fitted unobtrusively in confined spaces.

Many central heating maintenance companies recommend the fitting of a Magna Clean device, particularly after power flushing or the installation of a new boiler.

And they will also quote you a considerable sum to do so, along with a repeat fee for annual cleaning and maintenance!

However, a Magna Clean is self-powered, has no moving parts and is simple to install.

A Magna Clean can be purchased from most D.I.Y. outlets and comes in a number of designs that will fit into most central heating installations.

You can expect to pay between one hundred and one hundred and fifty pounds for the appliance including VAT.

Although the best time to install a Magna Clean is following a power flush, it is not a precondition.

The main advantage of installing a Magna Clean following a system flush is that the boiler or heating device has already been turned off and the system has been drained.

When the system is drained, the Magna Clean should be installed between the last radiator on the system and the system boiler. Generally, the device is fitted on the return hot water pipe just below the boiler.

The device should always be plumbed into the pipework in accordance with the manufacturer’s instructions. This is not a complicated procedure and can be accomplished in minutes.

The Magna Clean Pro 2 is perhaps the simplest device to fit and requires a 150 mm section of pipe to be cut out of the return hot water circuit. The device can then be securely connected into this gap with a spanner. The inlet and outlet valves are self-contained and the device can be removed and replaced anytime quite easily.

The Magna Clean Pro 2 also has an addition trap at the base of the device to collect non magnetic particles.

It is recommended that the Magna Clean magnet should be cleaned once a year, but it is probably wise to clean it more frequently, particularly on an older system where previous inhibitor and flushing practices may have been neglected.

To clean the magnet, close the inlet and outlet valves on the device. Release any pressure in the unit by turning the bleed valve at the top, and then unscrew the device top with the dedicated tool which is provided when the device is purchased. Then remove the magnet in its accompanying plastic sleeve.

The surface of the plastic sleeve will very likely be coated in black ferrous sludge, even after a short period of operation. It is the monitoring of this sludge that will give an indication of the level of contamination within the system and the frequency with which the filter should be cleaned.

To clean the magnetic filter simply run it under running water to wash away the sludge particles. The filter can then be inserted back into the device, the top replaced and the valves opened. The bleed valve on top should be operated to remove any trapped air.

Job done.

Beware of heating companies who, after installing a new boiler, suggest the installation of a Magna Clean device as an alternative to power flushing. Operating a new boiler without power flushing can invalidate the boiler warranty.

The Magna Clean installation should be seen as complementary to good central heating maintenance and not as an alternative.

It is estimated that the use of a Magna Clean device can knock up to sixty pounds of annual heating bills.

That has to be a saving worth considering.

Pressure Booster Pumps

Low water pressure, as an infrequent event caused by your water supplier carrying out maintenance on its mains network, or as the result of a burst mains at a distant location, it is something that cannot be avoided.

However, when it occurs frequently, often at certain times of the day, or when it is a constant problem, it can be a major issue. Showers and boilers, which require a minimum pressure to operate for safety reasons, will often not work.

Constant or inconvenient low water pressure can have numerous causes. It is a good idea to try to establish the cause before going to the expense of purchasing and installing equipment to boost domestic water pressure. Adding extra pressure to a damaged or partially blocked domestic water network may cause damage to the pump and plumbing.

Is the low water pressure limited to the domestic hot water supply or a problem concerning the entire water supply?

Where domestic hot water is supplied by a cold tank gravity fed system, a suitable head of pressure needs to be present to force water through the system. If the cold water storage tank is not at a suitable height, for example in a single storey house, the pressure may be low or at an unacceptable level.

If this is the case, a suitable water pump fitted into the hot water supply line at the exit point from the hot water cylinder will pump water on demand and at a suitable pressure to outlets.

It is important to ensure that the cold water header tank has an adequate capacity to feed the hot water storage cylinder when the pump operates and starts to empty it. Insufficient capacity may allow air to be drawn into the system.

For combi and sealed boiler systems and for general mains cold water, it is important to ensure that a low water pressure problem is not being caused by a leak. This could occur either within the boundary of your own property or that of any other property that is supplied by the service pipe.

It is also a good idea to check that your mains stop cock is turned fully on. It is not unusual to find pressure and flow problems caused by a stiff valve that a previous user failed to open fully.

The water company that serves your community will be able to determine whether low water pressure is the result of a leak or simply due to local demand on their side of the supply line.

Water supply companies sometimes minimise pressure within a local network to avoid causing damage to their already deteriorating systems.

Where a water company reports that water pressure and flow rates are within expected tolerances within its own mains network up to your boundary, the next step is to ensure that the problem is not being caused by other issues in the domestic network.

Over time, domestic pipe-work can become clogged up with encrustations of sediments and deposits that may be impossible to clear. If this is the case, re-piping is the only solution.

Occasionally, where lead and exposed copper piping remains in older buildings, the pipe-work can become accidentally crushed, restricting the flow around the property.

Sometimes following an investigation be the water supplier, it can be established that a low water pressure issue is not one that can be remedied by them. Perhaps your property is situated on a hill or low pressure is just an accepted inconvenience in your particular area,

If this is the case then a domestic pressure booster water pump could be considered as an option for increasing your water pressure.

There are a considerable number of manufacturers of pressure booster pumps and many different designs.

You should carefully establish that any pump you purchase is capable of supplying the required pressure. It is also important to consider where the pump will be located. It will need to be installed on the mains cold water pipe-work close to the stopcock but before any appliance.

When installing, it will require an appropriate electrical supply and an isolating valve on the pumped water flow line to enable future servicing.

Many booster pumps incorporate into their housing or require a pressure and expansion device. These devices prevent damage to the pipework system or attached appliances in the event of an excess pressure problem.

Bearing these points in mind, the size of the pump is going to be an important consideration to ensure that it, and its necessary fittings, will fit into the desired area.

Pressure booster pumps are designed to maintain a minimum pressure within the system and to operate automatically when they detect a drop in pressure caused by a demand. They then continue operating until the demand discontinues and a cutoff pressure is reached.

Most pumps operate quietly. When installing the pump consideration should be given to the surface upon which the pump is secured to minimise amplification of noise caused by vibration.

The actual plumbing of a pressure booster pump is an easy task. It is simply a matter of making an appropriate cut into the existing mains water pipework and attaching the pump inlet and outlet connections. If extra connections are required to accommodate expansion and pressure release mechanisms these are usually straightforward procedures.

If you are considering undertaking the work yourself, then pumps are readily available and installation instructions are usually quite comprehensive and easy to follow.

As with all DIY tasks, care should be taken to ensure that any work undertaken is within the capabilities of the person undertaking it. Poor workmanship can be expensive to correct. It is also wise to consider household insurance issues that may arise due to water damage caused by non-professionally installed appliances and subsequent plumbing failures.





DIY Copper Plumbing and Fittings

When it comes to carrying out maintenance tasks or simple repair work within the home, nothing can give as much satisfaction as DIY. The pleasure that comes from identifying and successfully completing the required work adds a certain feeling of being in control of, rather than being controlled by the technology and installations within the home.

It is also fair to acknowledge that being able to do all or part of the work that would normally require the intervention of a plumbing or heating engineer is likely to save a considerable sum of money. However, the ambitious DIY enthusiast should apply some caution to ensure that any work undertaken is within the scope of the enthusiasts’ skills and capabilities. Where DIY goes wrong, the cost of putting the situation right can be costly.

Although there are many materials available to the DIY heating and plumbing enthusiast, copper perhaps is the most widely used and most durable material.

All alternative pipe-work materials have their place and many offer an ideal substitute for copper for those who would prefer not to learn the basics of working with that material.

Yet learning how to install copper pipes and fittings can be a joy in itself and although skills are not learned overnight, the basics can be understood very easily. Getting the practice that would ensure any work carried out was as good as that of a professional would be another matter, but the same could be said when using alternative materials.

Copper is a proven, durable and reliable material, which is still the choice of artisan tradesmen, and when installed correctly makes the extra time it takes to install it aesthetically and visually worthwhile. It might be expensive to purchase when compared with some plastic alternatives, but copper and its brass fittings retain a scrap value and are completely recyclable.

Copper pipe comes in a three basic types. Thin, medium and thick-walled. Medium walled is a general type for domestic use. It can be purchased in rolls or in specific lengths. There is a flexible type of copper, suitable for repair work, and a rigid type of copper for general installations. Copper comes in a variety of diameters from 1/4 inch to 2 inches.

There are three categories of pipe fittings. The first category includes fittings designed for making bends and turns in the pipe. The second category has fittings made for joining or branching copper pipe. The third category is comprised of couplings, slip couplings, cast iron and other pipe-work adapters. All of these fittings can be used with either rigid or flexible pipe.

Copper pipe can be cut to the required lengths with either a dedicated pipe cutter or a hacksaw. It is important to ensure that the cut is vertical to the horizontal pipe to ensure a tight connection into the coupling. Once cut, the cut surface must be thoroughly cleaned externally with an abrasive material such as steel wool. The internal cut area must be reamed with a knife or suitable implement to remove any burs which, if not removed, can interfere with the smooth flow of water through the pipe causing erosion and corrosion.

Any coupling that is to be used must also be cleaned to remove debris that could affect the integrity of the join.

Copper pipe can be joined together in a number of ways. Brass compression fittings can be used to secure pipe joints. These rely on the deformation of an olive placed on the pipe. Pipe threads are wound with PTFE tape prior to compression. Applying a tightening procedure to the nut on the compression fitting compresses the olive into the joint with the copper pipe and brass fitting producing a watertight seal.

Adhesives are also available for joining copper pipes and fittings. These are designed to withstand water temperatures up to 300 degrees F. an adhesive might be suitable for use in some installations and repairs but would generally be regarded as unsuitable for extensive work.

Soldering and brazing are perhaps the most widely used methods of joining copper pipes. Soldering is suitable for general purpose. Brazing requires greater heat and metal fillers to replace the traditional solder. Brazing is best suited to systems that are likely to operate with a high working pressure.

Copper fittings can be purchased that are already primed with solder and simply require the joints to be cleaned. Flux should be applied to the externally cleaned pipe work and the internally cleaned core of the fitting prior to soldering. Flux is a compound that prevents oxidation of the copper pipe when it is being heated for the soldering process. Care should be taken with flux to avoid skin and eye contact or accidental ingestion.

Joints must also be completely dry to ensure a secure and reliable joint.

Prior to soldering or brazing, the pipework must be suitably secured to prevent any movement or vibration that might affect the integrity of the joint. Any vibration or movement will prevent the solder from setting properly and will result in a joint that is likely to fail.

For general soldering, the successful joining procedure is achieved through solder being drawn into the narrow space between the pipe and the coupling. This is achieved through capillary attraction. The pipe and joint area are heated to a point that will allow the solder to melt and run freely into and around the joint. Excess solder can cause problems if it enters the pipe-work interior.

Gauging the amount of heat required and the amount of solder to apply comes with experience gained through trial and error, however when heating the pipe with the blue part of the torch flame, a slight change in the flame colour from blue to green will indicate that the joint has reached a temperature suitable for the application of the solder. The solder should be applied carefully until it can be seen that the solder is starting to fill the joint cavity.

Care must be taken when using blowlamps to minimise the risk of fire or injury from burns. Soldered and brazed joints should be allowed to cool naturally prior to close inspection to establish whether the joint is secure. Where solder or metal filler has not completely filled the space in the coupling, the area can be fluxed again and reheated and a touch of solder or metal filler applied to remedy the situation.

It is possible to bend copper pipe to accommodate physical features in the building’s construction. This is often quicker than cutting, joining and soldering. The pipes can be bent using a specialised pipe bending apparatus. These are quite expensive to purchase and for DIY, a much cheaper alternative is a pipe bending spring. This is a length of spring coil, which is inserted into the pipe. With the spring in place, the pipe should be gradually bent to the required shape. If the pipe is bent with a sharp force, there is a risk that the bend will be formed with a rippled profile. This should be avoided.

Copper pipe cannot be successfully bent without one of these instruments.

Working with copper can be a satisfying procedure and is one that can be learned quite easily. As in all matters, practice with hands-on experience is the best way to learn.