topic Re: Heatlink cannot start boiler in Nest Thermostats

Heatlink cannot start boiler

bhaddow — Tue, 05 Oct 2021 10:38:48 GMT

We have two nest thermostats and two heatlinks, each linked to a different set of radiators. The upstairs thermostat is working fine. The downstairs thermostat seems to be unable to turn on the boiler. If I turn on both thermostats, and ensure that they are both heating (ie both orange) then all radiators come on. If only the downstairs thermostat is in the heating state, then the boiler does not start.

I am guessing the problem is with the downstairs heatlink. The downstairs thermostat shows no errors. What checks can I do?

The system has been working fine for several years,

best

Barry

Re: Heatlink cannot start boiler

AlexD — Mon, 01 Nov 2021 16:40:57 GMT

Thanks for all the information @bhaddow . I would be happy to try and assist.

First, how long have the thermostats been installed for and working before you first noticed this behavior?

Does any of them also control the hot water or are both just heating only?

Best regards,

AlexD

Re: Heatlink cannot start boiler

bhaddow — Mon, 01 Nov 2021 17:28:45 GMT

Hi Alex

Thanks!

Yes, the thermostats had been working normally for 4-5 years, and yes they control hot water too.

I had a conversation with a local engineer who suggested that the zone valve actuator may be faulty.

best

Barry

Re: Heatlink cannot start boiler

CristianC — Thu, 04 Nov 2021 14:55:30 GMT

Hey @bhaddow,

It does sound like the issue might be with the valve. Let me know if the installer checked it.

Re: Heatlink cannot start boiler

CristianC — Tue, 09 Nov 2021 13:25:11 GMT

Hello again. Just checking in. Do you still need my help?

Re: Heatlink cannot start boiler

bhaddow — Tue, 09 Nov 2021 13:42:22 GMT

It sounds like I need to change the actuator. I am not 100% sure that is the problem, but unfortunately cannot get anyone to look at it

best

Barry

Re: Heatlink cannot start boiler

CristianC — Tue, 09 Nov 2021 13:50:13 GMT

Got it. Have you tried to reach out to a Nest Pro?

Re: Heatlink cannot start boiler

bhaddow — Tue, 09 Nov 2021 13:51:04 GMT

Yes, but no-one available.

Re: Heatlink cannot start boiler

bhaddow — Sat, 20 Nov 2021 17:54:22 GMT

I fitted a new actuator and it makes no difference. Same behaviour as before. I am wondering if the valve is stuck (although it does turn) or there is some other electrical fault.

The valve actuator on the faulty circuit gets quite hot.

best

Barry

Re: Heatlink cannot start boiler

AnaM — Thu, 02 Dec 2021 15:14:09 GMT

Hey @bhaddow,

Apologies for the late reply. You are right, it could be a stuck valve, so the best thing to do in this situation would be contact a Nest Pro or even a regular installer to check the whole system. If the installer says that everything seems to be fine, then we'll take a closer look into the Nest system.

Re: Heatlink cannot start boiler

bhaddow — Wed, 08 Dec 2021 14:51:54 GMT

Hi Ana

Thanks. I changed the actuator (as noted above) and it does seem to be working normally now (despite what I said above).

best

Barry

Re: Heatlink cannot start boiler

AnaM — Thu, 09 Dec 2021 13:36:48 GMT

Hi @bhaddow,

This is great news, thanks for letting us know. Should you need any more help, we're a message away.

Re: Heatlink cannot start boiler

AnaM — Mon, 13 Dec 2021 13:51:43 GMT

Hey @bhaddow,

Since you no longer need assistance on this matter, I'll lock this thread now. If you need any help in the future, you can reach us out on any of our Support channels.