Noisy TRV's and vibrating pipework

[cynllunio]

Hi newbie here,

I hope someone can shed some light on my problem, I think it maybe a faulty bypass valve after reading some other posts but any help appreciated.

I have a Baxi 80 Eco combi boiler and new CH system installed about 3 years ago. I have 9 radiators, 8 with TRV's(bi directional), one small one has ordinary valves. No room stat. Heating sytem warms up and after a while I get sort of squealing from a TRV and some vibration from it and the surrounding pipework then it sets another one off sometimes and lasts for a few seconds or maybe a minute Then it might not happen for another half hour. Sometimes if I adjust the affected valve a little it will stop, but not always.

I understand the 80 eco has an integral bypass valve so I was wondering if it may have stopped working but this has been going on for nearly as long as the system has been in. Help please before we go nuts.

 

[kevplumb]

one small one has ordinary valves.

that's the other bypass
a lot of valves are not truly bidirectional might help to close the locksheild a bit

 

[cynllunio]

Do you mean the small radiator with no TRV's is the bypass? I was wondering if the radiator was too small and too far away from the boiler for the flow to be a sufficient bypass.

 

[JPC]

the rad with no trv is there incase the integral bypass failed.
if all trv's closed and the integral one failed ur water should flow and return safely thru the rad with no trv.
i dont think this is anything to do with ur problem...could u have a knackered trv ?...if the noise is from one of the trv...i'd change it

 

[cynllunio]

Its not just one TRV it sometimes goes around the house, but not every rad. Its foxed me. Although the TRV's are bi directional I was wondering if they would be better fitted horizontal instead of vertical where the flow of water is pushing directly agianst the valve trying to close. Any thoughts or experience?