Pipework / boiler noise.

[diydave13]

When I use the hot tap it heats water ok, but when turned off there is a noise running through the pipework and into the boiler.

This does not happen when running cold water and the heating works fine.

I did replace some radiator valves recently (approx 3 weeks ago) and in refilling the system I put in a desludger. I am yet to redrain the system and refill, including an inhibitor. Is it just a case of doing this procedure to stop the noise?

The boiler is a Baxi 80e combi boiler fitted about 3 years ago.

Can anyone suggest anything?

 

[bster]

Passive dead legs? - these are long runs of pipework which have been capped off in the past, when air collects in them the pressure surge (when you close the tap) compresses the air and starts to make the water in the system bounce around and thus creates noise.

But if it has only recently started i doubt that this is the cause unless you have drained the hot\cold water supply recently?

 

[diydave13]

No dead legs in this case.

I have not drained the hot and cold water recently, however I did turn the stopcock off whilst draining the heating system.

Originally when I started it all up again, I did lower cold water pressure as I had not fully opened up the stop cock. I thought this might have been the cause for the noise and have since opened the stop cock further.

This did not resolved the noise issue.

Any other ideas?