Vibrating thermostat

Foleyart

Hey there. The thermostat pictured in the attachment is part of the underfloor heating in the upstairs of my house. For some reason every now and again, the bloody thing starts vibrating, and the sound reverberates through the whole house. Does anyone have any idea of how to stop the damn thing. It wakes us all up during the night.

youtheman

You need to try find the source of the vibration. It's unlikely to be the TRV (thermostatic) head itself, maybe the pipe at the bottom of the TRV.

Everything that vibrates has a 'natural frequency'. And if you hit it then you'll know all about it. I have a thermostatic shower and at certain flow rates the thing makes a humming noise (I presume due to vibration). So I have to increase the flow to stop the noise.

The next time it vibrates I'd try grabbing various components on the system to see if you can identify what is the source of the vibration. If there is a flow control valve on the circuit then I'd try open it a bit to get more flow (as I have to do in my shower). When it begins to vibrate I would adjust the set temperature up to max (for a short while anyway). This will have the effect of letting more flow through. See if this causes the vibration to stop.

I think that as the system reaches the set temperature (as shown on the TRV head), the TRV head begins to close and throttle the flow. This causes a disturbance in the flow and it's hitting the natural frequency of the system. So you can either 'clamp' the system mechanically to stop the system resonating or just adjust the response of the system to avoid the resonant frequency altogether.

Sorry if this sounds long winded.

Foleyart

Hey Youtheman, thanks for the reply. It is definitely the thermostat, I suppose the only solution is to secure it mechanically to let us all have some sleep.
Cheers.