chatteringTRV's

[1JACKOFALLTRADES9]

my TRV some times start chattering but with a slight movement of the valve head from 2 to 3 or 3 to 2 it stops for a while ,

 

[stem]

Some valves are flow direction dependant and if installed the wrong way around will make a chattering noise as the room approaches the selected temperature. (The valve is trying to close against an opposing flow of water)

This would be the first thing to check. This type of valve will usually has an arrow on the valve body marking the direction of water flow.

 

[D_Hailsham]

Even bi-directional TRVs (an arrow pointing out of each port) will chatter if the pressure difference across the valve is too high. This is usually caused by incorrect balancing.

Do you have an automatic by-pass?

 

[Agile]

The lack of an auto bypass or incorrect settings are the most common cause although the problem can usually be bypassed by balancing of the always open rad if there is one.

Do you have TRVs on EVERY rad?

If so do you have a AUTO bypass?

Sometimes poor quality installers fit a bypass pipe with a manual valve on it. Adjusting that can also prevent chattering but a manual bypass can also create other problems which is why an auto bypass should be fitted.

Tony

 

[1JACKOFALLTRADES9]

Thanks for all the info we have TRV on all rads except bath room. we dont have auto bypass valve. I will try and balance the system and report back

 

[Agile]

Try to increase the flow through the bathroom rad then.

That may lessen the flow throught the others though.

An auto bypass would be the best solution.

Is your pump on setting "3" ?

Turning that down to the normal "2" would be better!

Tony