RTS1 to Nest E

[asmith1988]

Evening,

Having some trouble with changing from Drayton RTS1 to Nest E. Followed the nest app instructions and also https://www.diynot.com/diy/threads/nest-e-on-rts1-thermostat-british-gas-rs1.538439/ which seems identical to what I am trying to do!

So I've put black wire from 3 to NO on nest and Red from L to C on Nest.

I've set boiler to always on as suggested but the heating never turns off even with the nest app with heating to off.... Must have done something wrong here, any suggestions?

 

[CBW]

Is this on a combi boiler?

 

[asmith1988]

Yes it is a combi, vaillant. Added a photo of it below. Does it need to be set to on all of the time or on the timer setting with all time set to on?

 

[stem]

Sounds like you have done everything correctly.

The boiler timeswitch will now need to be permanently 'on' 24/7 and the Nest-e will control both time and temperature functions.

The brown wire in RTS1 L should be in Nest-e terminal (C)
The black wire with brown sleeve in RTS1 3 should be in Nest-e terminal (NO)
Isolate the neutral wire and tuck it out of the way

Does the manual button on the Nest Heat link turn the heating on/off?

Did anything happen during the installation process? for example any fuses blown? Did you connect the neutral wire to anything at any point? What happens if you reinstate the RTS1?

Bit of a long shot but if your system has a frost thermostat somewhere, and the temperature has dropped below its set temperature, that will override the Nest-e, but that would have also been the case with the original thermostat.

 

[asmith1988]

Yeah I think I accidently touched the neutral and earth wire at one point as I hadn't isolated everything properly, which tripped the fuse board but then moved the wires and turned it back on and it seemed ok. Could I have fried the PCB in the boiler then by doing that?

 

[CBW]

I wouldn’t have said so, do you have hot water? What’s the heating temp set to on the boiler? Press any button on the display, then top 2 buttons, what does the s number read?

 

[stem]

Yeah I think I accidently touched the neutral and earth wire at one point as I hadn't isolated everything properly, which tripped the fuse board

My suspicion, and hence my earlier question, is that when a short circuit occurs, if it goes through the thermostat it can weld the contacts in the thermostat together and so it's permanently on. Seen it quite a few times, on various heating controls. Sometimes you get away with it and sometimes you don't (more likely in my experience if there's a 13A fuse fitted instead of a 3A)

Having said that a short circuit would have to involve the Live, not the N and E as you describe.

If you remove the wire from the Nest-e NO terminal and then the heating doesn't come on then, that will show that the Nest is what is keeping the heating 'on' & and the boiler is OK.

 

[asmith1988]

I wouldn’t have said so, do you have hot water? What’s the heating temp set to on the boiler? Press any button on the display, then top 2 buttons, what does the s number read?

Yep, got hot water. Heating temp set to 60c on the boiler. If press the top 2 buttons it gives s.04

 

[CBW]

So your heating is on then. S.04 is heating on.
Turn it off on the thermostat and press the top 2 buttons and tell me what it states.