Tapping in heating

[sugmi700]

I have a tapping sound coming from my 3 way valve. I have changed the body and head and it is still there. I have TRVs all round and the system runs with a pressure relase bypass. I can vary the sound by adjusting the TRV in my en-suite. Have any of you come accross this or do you have any idea what might be causing this?

[eltelioni]

Sorry, I have no idea. This may seem a useless response, but I just wanted to let you know that you are not being ignored. Good luck!

[gucciman]

how loud is this sound?

quite often it can be a bit of debris in the system that is getting flushed about, esp bits of solder from the installation that have broken off.

apart from that i cant think of what it could be without hearing it.

[sugmi700]

Noise is quiet but consistent tap at constant time interval. Now have theory that it may be 3 way valve being knocked by repetitive pressure wave from dodgy TRV?

[gucciman]

thats a new one on me to be honest but im not saying your wrong.

[sugmi700]

If this is a flow problem, I'm going to start from scratch, rebalance the whole system, reset the pressure release on the bypass and then see. If tap is still there then I'm going to open fully each TRV in turn and see if any one stops the problem and if that doesn;t work, I'm goind to fit a surge inhibitor by the 3 way valve. Can you think of anything else that I can try?