My Nest 3 worked fine for over 2 years. A few weeks ago I had no heating and the issue could only be resolved by switching the heatlink to manual. Later that evening the Thermostat and the heatlink worked again. The same issue is now happening regularly - almost every day. I have to use the manual override to get the heating working and then later on the Thermostat and Heatlink start to work normally. I've factory reset the heatlink on a couple of occasions and reset the thermostat but no fix seems to last. In case there was wireless interference from somewhere I have now hardwired the thermostat and the heat link and they are definitely paired - both wired and wirelessly (confirmed by checking under "Settings" on the thermostat menu. Any suggestions? I guess the most obvious is that there's an intermittent fault with the heatlink which luckily manual override manages to bypass?
AnaM, thanks for your response. I did manage to webchat with a colleague on Tuesday who went through most of the same questions but I've answered them below as best I can in case you have additional suggestions. Following the diagnostics your colleague thought the heatlink seemed to be working OK and suggested contacting a Nest pro specialist for further diagnostics. I have asked my Central Heating Maintenance company to come out and check the installation (they don't cover the Nest itself but can check everything else)! If they can't identify a non Nest related fault then I can try to contact a Nest specialist. Ideally I would have liked to get hold of a heatlink to see if replacing the existing one fixes the problem - but they aren't available to buy separately.
What color is the LED on the Heat Link when this happens? Normally a single solid green light which changes to 3 green lights on manual override
What does the thermostat display show when this happens? Thermostat changes to "Manual".
What happens when you call for heat from the thermostat display? Does the display turn orange and say that the heating is on? This is the problem area. Call for heat doesn't work at all - only manual override. Note that Hot Water works as normal and fires up when the schedule tells it to do so.
What happens when you call for heat from the app? Same as using the thermostat/display - doesn't work.
Did you have any recent work done on your electrical, plumbing or heating system recently? Only normal annual service (about 6 months ago).
Did you have any recent power cuts? I told your colleague that we hadn't but in fact I think we did have an outage one overnight as i remember having to reset oven clocks and alarm. Perhaps 2 or 3 months ago?
Did you notice any pattern in this behavior? The problem is almost continuous now. At one point the call for heat did work but the system wouldn't switch off when the thermostat temperature was reached! I could only switch it off that time by using manual override! More generally it first happened about 6 weeks ago. It was OK for a few weeks and then started to happen once or twice per day. Now "call for heat" doesn't seem to work at all.
How many thermostats do you have? Just one.
Have you tried any troubleshooting steps? Everything recommended. I've factory reset the Heatlink several times and relinked it. I've reset the Thermostat and also disconnected from my router and then reconnected.
Thank you for your answers. If my colleagues over chat recommended that you check the heating system first, that'll be the best thing to do. If nothing seems to be wrong with it, you can come back to us and we'll sort this out.
CristianC, thanks for checking. I discovered a minor wiring issue (now fixed) so I'm back with my original problem in that most of the time the Nest and the Heating work fine but every so often the "call for heat" fails to work and I have to use the manual override (typically happens late morning for some reason). After a while (can be minutes or hours) the issue resolves itself and I can use the Nest Thermostat normally again. However, my NestThermostat and Heatlink are now wired together and are connected both wired and wireless so I am confident it isn't a network or radio frequency interference issue. The "click" test also works fine (as does the hot water on its nomal schedule) so my suspicion is that the Nest and Heatlink are probably OK and I actually have a transient issue with some aspect of the heating system - however as with unusual noises in cars those are notoriously difficult to isolate and track down! I haven't decided yet whether to get a Nest Pro first to run diagnostics to definitely prove it isn't the Heatlink (or that it is) and then get my boiler service management company to investigate the heating system OR to do it the other way round! Regards,
Hey @Tommyl. Thanks for getting back to me. It doesn't seem to be an issue with the Nest system. The issue might be with your valve, but we can't be sure until your heating system is checked. I suggest to ask a local installer or a Nest Pro to check it out.
Hey there, I haven't heard from you in a while so I'll be locking this thread. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the community. Thanks, AlexD.
