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daveakey · Joined: 19 Dec 2005 Posts: 2

Can someone stop me from pulling my hair out please ?

I'm replacing my ancient thermostat for a new Digistat RF3. Its connected to a Baxi Bermuda Combi (I know, I should be replacing that too !)
I have used the following connections which result in no action whatsoever from the SCR

Wiring from Boiler / Connection on Thermostat

Neutral (Blue) / N
Live (Red) / L
Earth (Green) / Earth
Call for Heat (Yellow) / 3

I have also bridged the Live (L) to 1 (Common), using a standard 240V live cable cut from an extension lead.

Even with the bridge, there appears to be no power on the thermostat, and no call on the boiler for the central heating.

When I re-wire the old thermostat, then the central heating works, so I figure the is no break in the wiring between thermostat and boiler.

Can anyone give me some guidance please ?

Have just found that the "call for heat" wire has 240v constantly running through. I would have thought that this would only happen when the thermostat was in operation.

HELP!

vince knight · Posted: Mon Dec 19, 2005 11:33 pm Post subject:

Do you have a permanent supply to the receiver as well as the stat supply?

daveakey · Joined: 19 Dec 2005 Posts: 2

I'm not too sure what you mean by that Vince - how do I check this ?

Cheers

vince knight · Posted: Tue Dec 20, 2005 7:28 pm Post subject:

The receiver unit needs its own 240v supply(from the heating supply) as well as the roomstat supply and switch live.
Thje mounting plate should say something like.
L permenant supply
N permenant neutral
1 heating on from boiler
2
3 switched live back to boiler

Only put a link between live and pin one if the boiler roomstat input is 240v and not Zero volt.