Water hammer banging pipes

[peterpies]

I'm getting banging pipes when a hot or cold tap in the house is turned on full, then turned off. Draining the system of water, then filling back up fixes the problem for 24 hours, then the banging returns.

I know dead ends in pipe work, can cause the problem. The heating system in the house was changed from conventional to combi a few years ago. Their was no pipe banging after this. But there are 2 dead end pipe runs where the hot water cylinder and expansion tank was. The pipes cant be removed as they run into a ceiling, but bleed valves could be fitted. I don't think these pipes are part of the central heating as their are another 4 pipes connected into 'U' bends that are getting hot when the heating is on.

Would this be the best place to start?

Thanks in advance for any input

 

[Riley]

Either way you probably need to get those dead legs sorted. If they are heating they could be the cause of the banging. If they are domestic water pipes still get em sorted as the water in them could stagnate and cause illness or worse

 

[Harvest Fields]

Any plumbing work completed recently?

 

[Matthew Score]

Do you have a water meter?

You need a water shock arrestor, if you have a water meter or double check valve on you incoming main it could invalidate any warranty on your boiler if you don't fit one.

https://www.NoLinkingToThis/p/refle...PPwKta_25h24YuvQJacaArovEALw_wcB&gclsrc=aw.ds

 

[SimonG]

When you drain the systems you are allowing the dead legs to fill with air. Which cushions the water hammer.
Cut out the dead legs and fit shock arrestors. Also make sure any pipes you can get at are securely clipped.