Nest not working

[valfedup]

Gosh, this page is scary, so many problems.... I'm already starting to think i should just get a proper thermostat... is there such a thing as technical support for a nest?  Or is this it, just post a problem and hope that the person who answers knows what they are talking about?  

So.... my nest appears to be working beautifully, it measures the temperature in the room accurately, but it has no control over the boiler at all.  I am just having to manually switch the boiler on and off when it gets too cold/hot.

I have tried re-setting the nest, re-starting it, unlinking it from my google account then linking it again, pressing the button on the wireless point beside the boiler,   Any other suggestions?  

There don't seem to be any error codes, the nest appears to think it is doing a great job.

When i try to look up instructions, there are so many I seem to hit on different ones each time i look.  Also i am a bit confused if it is a learning thermostat or just a thermostat.  I moved to this house 6 months ago.  The nest did appear to be working until about 2 weeks ago.

Any help gratefully received.  As long as it's someone who is qualified to advise on this 🙂

[laurentbourg]

Are you saying that the Nest stops calling for heat (does not glow orange) when it reaches its target temperature but the boiler does not stop and you have to switch it off at the breaker? What is your hvac system? (Boiler/radiators, electric forced air etc). Please also post a picture of your wiring base and the Nest model your are using. 

[valfedup]

Yes, that's right.  I have a worcestor combi boiler and radiaters.

[valfedup]

Hi Laurent, I would welcome your thoughts on my pictures and reply as my nest is still not working.

thanks 

[valfedup]

Not sure what wires you want to see?  Would i take the front off the white plastic thing on the wall?  Is it safe to do this or do I need to isolate it first?

[laurentbourg]

Is it possible that you are in manual heat mode? Please review enclosed documentation. https://support.google.com/googlenest/answer/9268632?hl=en#zippy=%2Chow-to-tell-if-manual-heating-is...

[valfedup]

I have checked the heat link.  It is switched on.  I re-set it and it came back on.  When I adjust the nest thermostat between heating on and off, the heat link makes a clicking noise as though it is responding to the thermostat.  However, it has no effect on the boiler.

[laurentbourg]

Ok thanks. Could you please upload a picture of the wiring diagram accessible in the Nest app? It is in the settings -> equipment -> wiring

Your heat link is most likely not wired properly to your boiler. It is usually 4 wires, 2 for power with live (L) and neutral (N), and 2 control wires usually on terminal 2 and 3, depending on your type of boiler. Was the Nest installed by a professional?

[valfedup]

We moved in to this house in may 21.   The nest was already here.  We had an engineer check the nest.  At that point it seemed to be working ok - although he offered to disconnect it and was surprised we wanted to keep it.  I had a nest in my last house and it worked great so was keen to keep it.  anyway what you are explaining sounds way beyond what someone who knows nothing about wiring should be dealing with - so we will get the engineer round again and work out if its economical to keep the nest or maybe its just not right for our boiler :(.  Thanks.  

[valfedup]

PS is that a solution? I keep getting emails asking me to tick "accept as solution"

[laurentbourg]

Yes considering this is most likely a heatlink issue I recommend you have it diagnosed by an HVAC professional unless you are proficient in electrical.

Keep us posted.