TRV problem

[Tony]

Good afternoon all,

Could someone help me with a problem I have with a bathroom radiator TRV?

The radiator works, gets hot, no problems but I don't think the TRV is working correctly. The TRV is fully open but the room temperature only stays around 16 degrees centigrade, I'd have thought, with the valve on full, the room would have been at least in the low 20's (it's only a small bathroom!).

The valve is a Landis & Gyr "Duogyr" (I think!).

I've popped off the cap and tapped the valve top to ensure it's not sticking but in all honesty the valve "sort-of" works!!...just not as good as it's supposed to I think!

Any ideas anyone?!, could I make further adjustments or is the valve destined for the bin?!

Thanks ever so much for any advice,

Tony

[Set Square]

Are you sure that the valve is on the correct side of the radiator, with regard to flow and return? Unless it's a bi-directional valve, the water

*must* flow through in the correct direction. If the flow is reversed, it could posibly explain your symptoms.

[Peter Andrews]

If the TRV is fitted the wrong way round the room simply gets hotter and hotter... been there and cooked until I worked out what I had done.

Does your radiator get cooler as the room warms up or does it simply stay hot all the time? If it stays hot all the time without the room getting any warmer it probably doesn't have the capacity for the room requirements.

Is there a reasonable temperature drop across the rad?

Peter

[Christian McArdle]

If the radiator gets hot, but the room doesn't, it doesn't suggest the TRV is faulty.

It is more likely that the radiator is too small for the room, particularly if it is well ventilated. Alternatively, the system needs balancing because the radiator doesn't get hot enough.

Christian.

[Aidan]

Is the bathroom radiator connected to the circuit that heats the stored hot water?

If so, is it gravity circulation or fully pumped to the hot water storage cylinder?

TRVs won't work well with gravity ciculation, the gravity differential pressure won't produce sufficient flow-rate due to the TRVs resistance, causing problems as you describe. I think you can get a special TRV for this application.

I posted this >24hours ago, but it seems to have got lost; apologies if it gets duplicated.