Replace wired Drayton Thermostat with Wireless RF3 Digistat

[GCR99]

Hi al

I have had to replace a wired Drayton Thermostat with a wireless RF3 as I believed it would be easier than running new cable under the floor etc.

Anyway they both use the same backplate (see pix) and are wired the same way (ie: N- blue, L- Red, Call-Yellow) So when I power off the boiler controls and power on with the new SCR in place, the boiler does not click on when I push the override. When the old dial thermo is put back it clicks on straight away. According to the instructions I cannot continue to pair up the SCR with the WiFi thermo until the overide is working.

Anybody seen this before
thanks in advance

 

[D_Hailsham]

Anyway they both use the same backplate (see pix) and are wired the same way (ie: N- blue, L- Red, Call-Yellow)

They may use the same backplate, but the SCR needs four wires. The existing red live wire comes from the timer/programmer CH ON terminal, so it is not a permanent live, which the SCR needs.

The correct wiring is:

A Permanent Live (e.g from wiring centre) to L
Neutral to N
Red to 1
Yellow to 3.

It's all shown in the Installation Instructions.

 

[GCR99]

Thanks for the info

To clarify one thing in the instrctions, Am I working to the "Combi boiler basic wiring layout" or "Zone Control Basic wiring layout" ?

 

[D_Hailsham]

To clarify one thing in the instructions, Am I working to the "Combi boiler basic wiring layout" or "Zone Control Basic wiring layout" ?

Presumably you know if you have a combi boiler.

However, the fact that you have three wires suggests that you do not. So the Zone diagram is the one to follow - or my instructions which are easier to follow!
The main difference is in the source of the mains power. Combi's usually have a direct mains feed, which is then used to supply the SCR. Regular boilers get supplied with mains voltage, via the timer and stat, when there is a call for heat.

 

[GCR99]

To clarify one thing in the instructions, Am I working to the "Combi boiler basic wiring layout" or "Zone Control Basic wiring layout" ?

Presumably you know if you have a combi boiler.

Thanks for your help D_Hailsham, actually I didn't know what a combi boiler is but I do now, google is a wonderful thing.