Combi and room stats again!

[freddyuk]

Sorry there have been many threads on this subject but i cant quit

resolve my question. I have a WB Greenstar HE combi which has its own programmer. I hav bought a simple TR2 room stat to control room temp.

Boiler manual says connect TR2 to terminals 3,4 and F (on boiler). It does not say what 3,4 and F do??

I assume i remove the link from the boiler circuit and connect the sta to 3,4 and F but the stat uses terminal 1 and 3 for L and N which i call and satisfied. Plus there is an earth connection. No obvious eart connection on the boiler where the TR2 is supposed to go?

Any ideas as any way i try it the boiler just says the link is remove

- it is not picking up the room stat

-- freddyuk

[Ed Sirett]

I had a quick look through the manual - the TR2 is special W_B room stat accessory (possibly using low voltage and/or digital interface) which wires as they say to 3 4 and F on BOTH units.

The 'simple' room stat you have which also happens to be (helpfully?) called a TR2 (?) has 1 and 3 which you should wire to Ls and Lr on the main PCB near the power input connector.

HTH

[freddyuk]

a double insulated unit ! My TR2 has an earth connection so i assume have completely the wrong stat for this application.

As for the TR2 being a generic terms well that certainly is confusing Many thanks for sorting that out

-- freddyuk

[Ed Sirett]

I don't think it's a generic term but simply the same model name given to two different units from two different sources.

Sometimes the manuals can be very misleading. One of my biggest difficulties is taking them literally as I tend to read between the lines a bit. I just remind myself that the [CORGI] inspector will tend to take a 'fundamentalist' / literal approach to reading the manual.

All the thermostats I use tend to be Class II devices anyway. However I can't see any obvious reason why you can't run a 3 core cable to the stat with Ls , Lr and E. But they may have some weird reason for why you can't