A major problem with central heating is air in the system. It can cause banging, whistling or howling noises as well as an increase in corrosion of the radiators and the boiler. Try fitting a de-aerator to the vent pipe. Choose a de-aerator suitable for connecting to compression fittings if you do not want to use soldered capillary joints. The de-aerator is shaped like a bottle and made of copper. It works automatically by 'beating' the air out of the water system by causing turbulence.
 

 
As the water gets hotter, the pipes expand. As the water start to cool down again the pipes contract. If the pipes are tightly fitting in the floor or wall, they will start to creak as they expand or contract.. If you know the location of the noise, try packing some lagging or a piece of felt around the pipes. It may be that the pipes ate sitting so tight, there is no room for movement. Try cutting a notch in the wood to allow for slight movements in the pipes. Make sure there are not two pipes touching. Place lagging or felt between them if possible. If a pipe appears to sag, use a strut of wood across the joist to sit the pipe on, padding with lagging or felt.
 

 
If there is a constant irritating humming in the pies, it is probably originating from the pump. Fit anti-vibration pump brackets to help reduce the noise. If this doesn't help, check that the speed of the pump hasn't been set too high. Another cause of humming in the pipes is due to the volume of water they have to carry around the system. The pipes may be too small for the amount they have to carry.
 

 
When the flow of water is halted quickly - by turning a tap on and off quickly, a set of shock waves can be set up and carried along the pipes. This can often result in banging, which gets progressively louder as the wave bounces about and takes some time to quieten down.

Possible causes:
Faulty stop-cock - stop-cocks can become faulty when the packing becomes loose and the jumpers wear out.
Faulty taps - again the packing can become loose and the jumpers wear out.
Faulty ball valve in the cold water storage tank
Water Flow - The flow of water is too fast.

If you fail to cure the problem, severe cases can be dealt with by installing a type of shock absorber in the mains system.
 

 
If the flow of water through the boiler is insufficient, then the boiler can be noisy. It is very important to have the correct water flow rate, especially in wall-hung boilers.

Steam bubbles can cause hot spots in the boiler, which can produce loud bangs. The cause is usually due to corrosion and scale forming in the boiler. Add non-acidic cleanser plus a de-scaler .to the feed and expansion tank.
 

 
Plumbing > Problems associated with radiators
 

 
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