Bypassing NEST thermostat

[233sqn]

Hello all

My son's Nest thermostat has packed up (another story) but to get him going we have bypassed it by adding a switch as per the picture. The boiler is a simple Potterton combi. It seems to work just fine by manually switching it on and off but I just want to make sure I'm not causing any long term damage or doing anything dangerous by doing this?

 

[233sqn]

I should have added that the black and grey wires now being switched come from the boiler and were previously wired to 2 and 3

 

[muggles]

Those are the OpenTherm terminals and should only be connected to OpenTherm connections. The big button in the middle provides manual switching

 

[denso13]

I should have added that the black and grey wires now being switched come from the boiler and were previously wired to 2 and 3

Should work ok if the Nest is totally goosed.

 

[CBW]

Those are the OpenTherm terminals and should only be connected to OpenTherm connections. The big button in the middle provides manual switching

How do you know they’re opentherm?

 

[muggles]

How do you know they’re opentherm?

Because they're marked "OT1" and "OT2" and because I've fitted well over 100 of them

 

[denso13]

Because they're marked "OT1" and "OT2" and because I've fitted well over 100 of them

I don't think they are connected to opentherm, it just looks like it. They used to be connected to 2 and 3 and the OP has simply bridged them out. They exit the flex and go straight to some sort of terminal block we can't quite see.

 

[bernardgreen]

I should have added that the black and grey wires now being switched come from the boiler and were previously wired to 2 and 3

which are not the OT1 and OT2 terminals

 

[ericmark]

Because they're marked "OT1" and "OT2" and because I've fitted well over 100 of them

But he said

were previously wired to 2 and 3

So opentherm not being used.

My worry would be if 230 volt some one touching wires.

 

[SpecialK]

Have you contacted google about the nest? I believe this is a common problem and they will send you a new one and some money to get it changed out?

 

[233sqn]

Should work ok if the Nest is totally goosed.

Yep.... nothing, its dead, just wont connect. My son has Googled it and seems like its a fairly common issue and they are sending out replacements.

 

[233sqn]

Those are the OpenTherm terminals and should only be connected to OpenTherm connections. The big button in the middle provides manual switching

Nothing at all when pressed. The manual switch I have added seems to be doing the same thing though.

 

[233sqn]

Have you contacted google about the nest? I believe this is a common problem and they will send you a new one and some money to get it changed out?

Yes... he has a new one coming. Didn't know they pay towards the change out though! I'll let him know and he can chase them on it!

 

[magicmushroom666]

I'd put some tape over those connections in the white block at the bottom, you can see some exposed copper hairs that have the potential to be live.