Draining the Radiators
1. Turn off the central heating. Once the water has cooled down, switch off the pump and shut down the two stopcocks to the two tanks in the loft (the cold-water supply tank and the feed-and-expansion tank).
2. Go to the boiler and locate the draincock at the lowest point in the system. Push one end of a garden hose out into the garden or into a drain.
3. Open the draincock with a spanner. When water stops running out of the hose, go up to the top of the house and then, working your way down from the highest radiator in the system, open the bleed valves.
Cleaning & refilling the system
1. Once the system is empty, introduce a proprietary descaler into the system as recommended by the manufacturer. This will usually involve turning off the draincocks and bleed valves, pouring the descaler into the feed-and-expansion tank in the loft, running the boiler and then flushing the system.
2. Close the draincocks and radiator valves and open up the stopcock to the feed-and-expansion tank in the loft. When the system is full of clean water, go to the lowest radiator in the system and bleed the valve to let out the trapped air. Gradually work up towards the topmost radiator in the system.
Cleaning (or replacing) a radiator
1. Roll back the carpet by the radiator and cover the surrounding floor with old towels. Run a path of plastic sheet from the radiator to the door of the garden, so that you can carry the towel radiators outside without dribbling water across the floor covering.
2. You can use your hands to turn off the control valve at one end of the radiator, but you will need an adjustable spanner to turn off the lockshield valve at the other end.
3. With a couple of bowls, a bucket and old cloths at the ready, and with a helper close at hand, go to the control-valve end of the radiator and use the two spanners to to disconnect the radiator from the valve, all the while being ready to guide the water into a bowl.
4. When the water has stopped flowing out of the control-valve end of the radiator, unscrew the connection at the lockshield-valve end and lift the radiator from it's bracket. Carefully take the radiator from the room and carry it out into the garden.
5. Wash out the old radiator with the garden hose, wind wraps of PTFE tape around the threaded tails, refit the connections, open the valves and bleed the air vents and the job is done. Alternatively, replace the radiator with a new one of the same size.
Cleaning the pump on the boiler
1. Turn off the power at the main fuse box or consumer unit.
2. Go to the boiler, use a screwdriver to remove the cover plate from the pump, unscrew the connections and disconnect the wiring.
3. With a bowl, bucket and old cloths to hand, turn off the service valves taps at either side of the pump, undo the connections with adjustable spanners and lift the pump clear.
4. Take the pump into the garden and use the hose to flush out all the sludge. When you have cleaned it thoroughly (or purchased a new one of the same size and specifications), fit new fibre washers and use a spanner to fix the pump back into place.
5. Turn the valves back on, reconnect the electricity and run the boiler. Finally, use a screwdriver to bleed the large screw valve at the centre of the pump, and the job is done.
Balancing the radiators
The object of this exercise is to ensure that the flow of water through the radiators is balanced - by adjusting the individual valves - so that all the radiators reach the required heat. (or, put another way, if you simply open all the valves to their full extent, the flow of hot water from the boiler will find the swiftest route round the system, with the effect that some radiators will run very hot while others stay cold). You will need a pair of radiator thermometers, which can be hired from a tool-hire shop.
1. Turn off the heating system. When it has been off for a few hours and the water is cold, go to the radiators and turn all the valves full on - the hand-operated valve at one end of the radiator and the spanner/pliers-operated lockshield valve at the other end.
2. If you now turn the boiler on and feel the radiators in turn, you should be able to work out the order in which the radiators heat up, and the direction of flows in and out of the radiators.
3. Use tabs of masking tape to label the radiators with the order in which they heat up.
4. The next operation will take some time. Take the pair of thermometers and clip them to the flow and return pipes just below the valves. Now, starting with radiator number one, close the lockshield valve, and then open it little by little, until the temperature on the 'flow' (the hot-water-in end of the radiator) has reached a point about 10-11°C hotter than the temperature on the 'return' (the cold-water-out end of the radiator).
5. Continue making adjustments to all the radiators in turn until you get to the end of the circuit. If you have got it right, the valves on radiator number three will be slightly more open than those on radiator number two, and so on up the list, to the point where the valve on the last radiator in line will be almost full on.
Article reprinted from The Complete Book of Home Plumbing by Julian Bridgewater
1. Turn off the central heating. Once the water has cooled down, switch off the pump and shut down the two stopcocks to the two tanks in the loft (the cold-water supply tank and the feed-and-expansion tank).
2. Go to the boiler and locate the draincock at the lowest point in the system. Push one end of a garden hose out into the garden or into a drain.
3. Open the draincock with a spanner. When water stops running out of the hose, go up to the top of the house and then, working your way down from the highest radiator in the system, open the bleed valves.
Cleaning & refilling the system
1. Once the system is empty, introduce a proprietary descaler into the system as recommended by the manufacturer. This will usually involve turning off the draincocks and bleed valves, pouring the descaler into the feed-and-expansion tank in the loft, running the boiler and then flushing the system.
2. Close the draincocks and radiator valves and open up the stopcock to the feed-and-expansion tank in the loft. When the system is full of clean water, go to the lowest radiator in the system and bleed the valve to let out the trapped air. Gradually work up towards the topmost radiator in the system.
Cleaning (or replacing) a radiator
1. Roll back the carpet by the radiator and cover the surrounding floor with old towels. Run a path of plastic sheet from the radiator to the door of the garden, so that you can carry the towel radiators outside without dribbling water across the floor covering.
2. You can use your hands to turn off the control valve at one end of the radiator, but you will need an adjustable spanner to turn off the lockshield valve at the other end.
3. With a couple of bowls, a bucket and old cloths at the ready, and with a helper close at hand, go to the control-valve end of the radiator and use the two spanners to to disconnect the radiator from the valve, all the while being ready to guide the water into a bowl.
4. When the water has stopped flowing out of the control-valve end of the radiator, unscrew the connection at the lockshield-valve end and lift the radiator from it's bracket. Carefully take the radiator from the room and carry it out into the garden.
5. Wash out the old radiator with the garden hose, wind wraps of PTFE tape around the threaded tails, refit the connections, open the valves and bleed the air vents and the job is done. Alternatively, replace the radiator with a new one of the same size.
Cleaning the pump on the boiler
1. Turn off the power at the main fuse box or consumer unit.
2. Go to the boiler, use a screwdriver to remove the cover plate from the pump, unscrew the connections and disconnect the wiring.
3. With a bowl, bucket and old cloths to hand, turn off the service valves taps at either side of the pump, undo the connections with adjustable spanners and lift the pump clear.
4. Take the pump into the garden and use the hose to flush out all the sludge. When you have cleaned it thoroughly (or purchased a new one of the same size and specifications), fit new fibre washers and use a spanner to fix the pump back into place.
5. Turn the valves back on, reconnect the electricity and run the boiler. Finally, use a screwdriver to bleed the large screw valve at the centre of the pump, and the job is done.
Balancing the radiators
The object of this exercise is to ensure that the flow of water through the radiators is balanced - by adjusting the individual valves - so that all the radiators reach the required heat. (or, put another way, if you simply open all the valves to their full extent, the flow of hot water from the boiler will find the swiftest route round the system, with the effect that some radiators will run very hot while others stay cold). You will need a pair of radiator thermometers, which can be hired from a tool-hire shop.
1. Turn off the heating system. When it has been off for a few hours and the water is cold, go to the radiators and turn all the valves full on - the hand-operated valve at one end of the radiator and the spanner/pliers-operated lockshield valve at the other end.
2. If you now turn the boiler on and feel the radiators in turn, you should be able to work out the order in which the radiators heat up, and the direction of flows in and out of the radiators.
3. Use tabs of masking tape to label the radiators with the order in which they heat up.
4. The next operation will take some time. Take the pair of thermometers and clip them to the flow and return pipes just below the valves. Now, starting with radiator number one, close the lockshield valve, and then open it little by little, until the temperature on the 'flow' (the hot-water-in end of the radiator) has reached a point about 10-11°C hotter than the temperature on the 'return' (the cold-water-out end of the radiator).
5. Continue making adjustments to all the radiators in turn until you get to the end of the circuit. If you have got it right, the valves on radiator number three will be slightly more open than those on radiator number two, and so on up the list, to the point where the valve on the last radiator in line will be almost full on.
Article reprinted from The Complete Book of Home Plumbing by Julian Bridgewater