TRV's on a new system

[Philip]

Hi,

I have recently had a new CH system installed. An Ideal Isar condensing combi and 13 rads, 12 of them with Optima TRV's.

My question is - why do the TRV's act like on off switches? set to 5, the rads are stonkingly hot. set to 4 and they are cold! Is the range only operative between 5 and 4?

Cheers

Philip

[Roger]

The message from "Philip" contains these words:

Assuming they are working properly:

5 will regulate to a higher temperature than the current room temperature and the valve will close when the room (or rather the air close to the valve) reaches that temperature.

4 will regulate to a lower temperature than the current room temperature and the valve will only open and the radiator heat up when the room temperature falls significantly below that lower temperature.

[Set Square]

[Set Square]

[Sorry about the previous empty post - finger trouble!]

They're operating based on the surrounding air temperature. If you open all the doors and windows and let in the arctic air, they'll be stonking hot on

4!

Chances are that the room in question is picking up heat from other surrounding rooms to achieve a level 4 temperature without that particular rad needing to be on.

If they're *all* on 4, and are *all* cold - wait a bit for the house to cool down a bit, and they'll all come on.

[John Rumm]

Also check that you don't have the room stat set so low that it cuts off the boiler before the rad valves get a chance.