help wiring a Drayton Digistat +3

[duns]

Hi folks.

Attempting to install a Drayton Digistat +3 programmable thermostat, but finding it tricky.

Quick backstory - property has a Vaillant ecoTEC pro 28 boiler, previous setup had a British Gas WR1 wall mounted receiver unit coupled with a British Gas RC Plus programmable thermostat.

The previous RC Plus unit doesn't work anymore, have tried replacing all batteries but no joy. So bought this Drayton Digistat +3, without realising it wasn't the RF model. Fine, I thought, I'll just remove the WR1 unit and replace it with this new controller, I don't really want to have a remote unit anyway that'll get lost or trampled on or chewed by the dog etc.

This is where I'm stuck. I opened up the WR1 but see a lot of wires that mean little to me. I get there's a live, neutral and ground, but there's also two grey wires, one dark and one light colour that I don't know what they do. These five wires all come from the boiler itself.

There's also a shorter live, neutral and earth that hooks into the wall mounted switch that powers the boiler on or off. I take it this is the power for the WR1 unit. The +3 unit I have is battery powered and only needs two wires apparently, but I don't know which ones. Do I need the mains powered unit and not the battery only? I understand this +3 doesn't need the neutral and ground, but it does need a permanent live and a switched live, but I can't be sure which ones I need to connect up from the existing installation.

Appreciate any help here massively.

 

[duns]

Is it a case of it doesn’t matter which of these two grey wires go to permanent live and switched live?

 

[Taylortwocities]

The wires on 1 and 3 are the two you need on the contacts of the Digistat. the live , neutral and live wires will need to be terminated in separate insulated terminal blocks. They are probably the power feed for the boiler.

 

[duns]

The wires on 1 and 3 are the two you need on the contacts of the Digistat. the live , neutral and live wires will need to be terminated in separate insulated terminal blocks. They are probably the power feed for the boiler.

Thanks, I did think that was the ones but does it matter which way round they’re wired into the Common and On terminals on the new +3 unit?

Also, for the live neutral and ground currently coming from the switch, do I need to connect them together with the live neutral and ground on the feed to the boiler (that might seem like a dumb question, just want to be sure)?

 

[Taylortwocities]

Doesn’t matter which way round they go. It’s just an on switch.

Yes of course you must connect them together or the boiler will not have any power!
You have three other pairs of wires on the old stat
They are the L, N and E. they need to stay connected together. So you’ll need a bit of insulated chock block.

 

[duns]

Doesn’t matter which way round they go. It’s just an on switch.

Yes of course you must connect them together or the boiler will not have any power!
You have three other pairs of wires on the old stat
They are the L, N and E. they need to stay connected together. So you’ll need a bit of insulated chock block.

Thanks, yeah seems obvious now I think about it. Cheers for your help, much appreciated.