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Banging central heating pipes throughout the house

Our central heating pipes are very noisy, with regular banging throughout the house. I understand that, when coming on from cold, we should expect to hear noises as the pipes heat up and expand, but we get regular banging even when the heating has been on for hours.

In particular, we get it a lot when we briefly run the hot water (e.g. to wash hands), when the combi boiler switches to heat the water and then back to the heating. When switching back, there are a lot of bangs.

It's an old house and the pipes are all copper. The boiler is a Potterton combi boiler. We've tried securing some of the pipes under the floor where it was most noisy, but it hasn't made much of a difference.

Could it be caused by sludge in the system, where water is being restricted flowing through the pipes? If so, could be solved by a powerflush? The radiators themselves heat up ok and get nice and hot, with not a huge difference between the top and bottom. I've also bled them all frequently and they never need doing.

Any suggestions would be much appreciated - thanks!

4 Answers from MyBuilder Plumbers

Best Answer

Normally biggest problem for noisy copper pipes is they touching each other flow with return pipes.The option if its possible to remove some floor boards and fit small peaces of insulation (rockwool,isover or similar fire resistant insulation) between pipes where they touching each other.


Answered 20th May 2018

it could be water hammer on the hot pipework due to loose pipework or pipework trapped and unable to expand,on the heating it could be a build up of sludge in pipes.


Answered 6th Mar 2018

Should like there sludge in the system and heat exchanger good power flush and a filter fitted will sort it before it get to bad and you need a new heat exchanger


Answered 7th Mar 2018

You could check your mains cold water pressure this too can cause water hammer when taps are turned on and off.


Answered 8th Mar 2018

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