I have TRVs fitted to most of my radiators and all of them are subject to a vibrating noise at times. I stop the noise by turning the TRV control in either direction until it stops. It has been explained to me by a plumber that the noise is due to the valve 'bouncing' when the TRV activates and, either closing or opening, is at a point where the valve is just opening or just closing. My turning the control knob then stops it by either releasing it to be more open, or shutting it altogether. Can anybody advise me as to the solution to this annoying and on-going problem? The TRVs are uni-directional, by the way, i.e. the valves are designed for the flow of water to be in one direction only rather than the more common bi-directional valves. Please help as at night the noise wakes the whole house!

DenDen46, January 2011

Thankyou Brian and thankyou Boiler Bill.
I established that it was the flow & return going in the wrong direction round the system. As this was true for all the rads I concluded that the simplest and quickest remedy was to reverse the flow. I drained the system and cut the flow & return pipes between the boiler and where they entered the system pipework and, with a couple of full bore flexis, reversed the connections so that the flow was in the right direction. Noiseless thereafter!

DenDen46, January 2011

Make sure the valves on the other end of the rads are fully open and drop the pump speed down to 1, if this doesnt work try draining the system and adding sentinel x200 noise reducer as this is designed to disperse air quickly in heating systems

boiler bill, January 2011

you've probably fitted them to the return side of the rads with the system cold turn on heating then check each rad to find out which pipe gets hot first this is the flow side fit the trv's to this side

brian, January 2011