Replace a boiler controller (SP Connect) (Ed.)

[simonharries]

Hi

I'm trying to help my son and replace his (defunct) Scottish Power Connect controller with a basic controller (for a combi boiler) and a smart thermostat.

The controller I have in mind is a https://www.draytoncontrols.co.uk/product/lp111 and the smart switch is a AWOW Smart Thermostat (needs 3 wires).

The question I have is:

As the SP Connect used a wireless connected thermostat, which wires do I need to extend to the new smart thermostat?

Does that make sense?

Photos show back plate and unused wires of current setup.

As ever - your expert advice very much appreciated.

 

[stem]

The wires with the brown tape are the heating control wires. They should be wired in series with the switch of room thermostat. When the switch inside the room thermostat closes it completes the circuit and turns the heating on.

Sorry, I've never seen a AWOW Smart Thermostat. I'm assuming it will have instructions, so you will have to work out where they go at that end. I guess it will also need a 230V supply to provide it with operating power.

 

[simonharries]

Thanks stem - that's very useful.

The AWOW is as below - I have one in my place.

 

[stem]

3 and 4 would correspond with the two terminals I show. Even the symbol is the same.

But the problem will be that when the timeswitch switches off, then the Live to the thermostat which comes via the link wire between 7 & 4 will be lost too, so a separate permanent L is also required to keep the thermostat powered.

However, is the AWOW just a thermostat? or does it include time control functions as well? If it does, then there's no need for a programmer as well and it can be left permanently on 24/7 to keep the thermostat powered.

 

[simonharries]

Thanks - understood.

I have my heating on permanently and operate it from the thermostat only.

The app allows timings to be set (weekdays/Sat/Sun) so there's full control via the thermostat/app. The controller I plan to use is there as a back up only - in case the thermostat or app failed and it needed to be replaced quickly with something manual.

 

[stem]

The controller I plan to use is there as a back up only - in case the thermostat or app failed

Unfortunately, the timeswitch wouldn't do anything if the thermostat failed. Both the timeswitch and the thermostat need to be 'on' for the heating to work. So, if the thermostat failed 'off' then the heating wouldn't work even if the timeswitch were 'on'. But the wiring mod could be reversed in an emergency to get you by.

 

[simonharries]

Hi - yes. I meant that I could just replace the thermostat quickly, with a spare manual one, to get it working again - on the timer.

Then order a replacement smart thermostat and fit that when it arrived.

Thanks stem - very good of you to take time to keep me right and make sure I'm heading in the right direction