Noise from TRVs Driving Me Mad!

[2point8ghiax]

We've just moved into a bungalow that had a new combi and TRVs fitted about 2 years ago. With the heating on, the TRVs make a loud hissing noise (similar to a toilet cisten filling or a slow running tap) at various settings. The TRVs are made by Caleffi.

For example, the one in the living room will be quiet at setting 3 on the the TRV, then later it will start hissing. So I change valve setting to 5 which sorts it for a while. It then starts hissing again, so I turn it to another setting to get some peace. This can go on all night!

The valves are fitted with the arrows in the correct direction of flow. Are all TRVs noisy? What's the solution. P.S. its a Glow worm 30 CXi boiler.

 

[swbjackson]

The hissing is as the valve is starting to close. Have you got a rad with no TRVs fitted? Sounds like you may need a bypass fitting or the integral (if there is one) bypass in the boiler adjusted.

 

[2point8ghiax]

Thanks for the reply. Yes, the radiator in the hall near the stat doesn't have a TRV. It has standard valves. I have just had a look at this radiator and discovered that the wheel head valve on it is almost closed (previous owner). Do you think that this is the problem?

I will open the valve fully and see how I get on.

 

[D_Hailsham]

This can go on all night!

You keep your heat on overnight??!! What temperature are you setting it to overnight? Do you hear the rad noise during the day or just at night?

The previous owner may have shut the wheel valve on the hall radiator to reduce the output so the hall thermostat does not operate before the TRVs work.

The 30cxi has a two speed pump and adjustable auto bypass; these may need adjusting. The radiators may also need balancing.

 

[Agile]

I suppose you are one of these people who dont have a TV and sit quietly seeing if you can hear the rad valves?

The system should have had an auto bypass valve fitted but instead relied on this one rad without a TRV.

Open each valve on that one rad about 2 turns and it will probably solve the problem. So will listening to the radio or TV.

Tony

 

[D_Hailsham]

Open each valve on that one rad about 2 turns and it will probably solve the problem.

It will also put the system completely out of balance.

 

[Agile]

Thats probably not far from the balance point anyway.

Few systems with TRVs are ever balanced.

Most installers seem to think ( wrongly ) that its not necessary to balance systems with TRVs fitted.

Mostly the same installers dont think its necessary to range rate the heating output either. ( Wrong as well ! )

Tony

 

[Statia]

I suppose you are one of these people who dont have a TV and sit quietly seeing if you can hear the rad valves?

Time of the month for you is it Tony?