Nest Thermostat Won't Turn Off Heating

[Spenc91]

Hi,

I have had Nest Learning Thermostat in my house since 2017 and has worked great with no issues until a few weeks ago whereby the heating would turn on but when it reached the set temp it didn't turn the Boiler off so the house continued heat. After checking all the wires were still seating correct (which they were), i factory reset the Thermostat which didn't resolve the issue. I then changed the Equipment from Combi Boiler to System Boiler and the boiler instantly turned off. The App the was missing the feature to turn the heating on but that wasn't a massive issue as I was still able to turn the heating off and back on via the Thermostat.

Fast forward to this morning (09/11/2021) the heating came on as Scheduled however when it reached the set Temp it didn't turn off again. the only way for me to turn the heating off is to cut all power to the boiler. This happen as i was leaving the house for work so i was not been able to play around with the settings (i plan to tonight) to see if switching it back to Combi Boiler would work.

Has anyone else had the issue recently and know a Fix?

thanks in Advance 

[ajp2001]

This has happened to us in the last couple of days , the heat doesn’t seem to stay on at say 20c as programmed but will definitely stay constantly warm . I have also noticed that our water isn’t getting as hot out of the taps as normal ? As it happens we have a British Gas service on Friday so we will see I suppose 

[Spenc91]

I have the opposite issue where the heating doesn’t turn off! 

[AndyC66]

I have same issue , hot water is off, and thermostat shows dark, I have selected a low temperature 12c to make sure heating is off.

but boiler is still firing up and radiators still hot

was ok until a few weeks back. I got boiler serviced, and all was ok with that. 

Frustrating, how can I get back to system switching off again?

[Vishalsharma81]

Hi. Did the issue get resolved and how please?

[Jmac0804]

I just had to turn the breaker off to get the heat to stop. Turning the heater off at the thermostat or on the app didnt work.

[MartynM]

Did you happen to get a solution? Mine is just installed and it's frankly useless if it's not going to turn the radiators off when the house reaches the desired temperature...

[inHen]

Same with ours. It only started doing it recently but it’s done it a couple of times over night and we’ve been woken up sweating and had to switch the whole heating system off at the circuit breaker.

There doesn’t seem to be a pattern of circumstances as it’s done it from preheating in the morning and my wife has just told me that she came home for lunch last week and the thermostat was set to 18*c but the house was over 25*c!

Perhaps a recent software update is to blame although I would have expected Nest to put out a bulletin and schedule for remedying the fault. It’s cost us about £48 extra in electricity bills as we’re an all electric household.

 I haven’t seen any responses from Nest on the issue yet.

[Spenc91]

Yes! This is exactly the same we have! Nest Support advises I get a tech out to do a  continuity Test on the heat link 

[inHen]

I’m an electrician and I can confirm that you don’t need a “tech” to check the continuity of your heat link because your heating wouldn’t switch on without continuity because it wouldn’t switch on at all without.

 I’m certain it’s a software problem because the heat link isn’t cutting the run signal. It’s not a momentary signal to run and a momentary signal to stop its on or off.

[Vishalsharma81]

Hi. Did the issue get resolved and how please?

[Spenc91 · Accepted solution]

Thanks for the info. I to didn’t believe them as all the checks we carried out over the webchat seem to be working fine so I spent the last two hours googling. Please note, I have no knowledge on heating/plumbing/electrical, it’s all shelf taught so if the bellow seems a lot of rubbish then it might just be but Here is what I found and seen to resolve my issue for now.

i noticed when the Nest thermostat reached the set temperature, it signalled the heat link to turn off the central heating switch valve (Myson power extra) but I couldn’t hear the valve close. After banging this with a screw driver it shut and the heating/ CH pump shut off. It’s now working as it should so I wonder when/if the central heating “valve” get stuck open then the boiler/CH pump stays on. When I turn on / off the heating now I can hear the value open / close.

[Noggie]

I’m having this issue right now, was working fine and now the heating won’t turn off. Thermostat and app set to 15C, house at 22C and boiler still on. Wasting so much oil. We’ll try this combi thing 

[Ctrot]

I am having the same issue.  Really disappointed.  Sounds like a software issue that has not been resolved.

[Spenc91]

Hi Noggie, 

My issue was due to the central heating value getting stuck open. Once I got this fixed, the heating as been fine 

[Natashancaiden]

Where I’d this central heating value? I’m having the same issue and my HVAC system was just replaced inside and out in Aug 2021 with a brand new Train system 

[Jmac0804]

Did you keep the nest thermostat or give up?

[ryancohen]

I am having a similar issue.... I turned the Heat complete off on the Nest. However, when putting my hand on the forced hot water pipes, it is still relatively hot. Its about 36 degrees right now, and I have had the heat turned off for hours, and the house is still maintaining warm temp....

[Isadisa]

We have also been having this issue for a couple of weeks. I did all the trouble-shoiting stuff. Reset everything etc.. It co tinues to blow hot air even when in the off position or on cool. I know nothing about hvac and I need to get this heat off before I melt. S.O.S.

[yardax]

Im having this issue too. But ive discovered with my heater if i use the app to turn the hot water on and then off again straight away, then the heating turns off. 

[DL1221]

Has anyone found anything on this? Having this issue here, too.

[RayC]

I posted a similar problem yesterday.

[RayC]

I spent a couple of hours on a Google Nest chat repeating the problem to be told that I should get Heat Link continuity wiring checked by electrician (why, if it is firing?) and then plumber to check valves. It took a long time to explain over and over the obvious issue, but I had to check history which did not record that the boiler was firing when in fact it went on heating at night until I manually had to switch off the system. So it is thought that it is not the controls at fault, but I am not yet convinced. Could it not be a failure of the Nest controls which are not doing what they display?

[Chris18]

Were you able to figure this out? I have a 2 wire system as well. I have mu heat set at 68 but the house stays between 75 and 77. I have a black wire that was not in use with the prior system.

[DL1221]

Helpful, thanks. I also spent time on with google support yesterday. Similarly, had to explain the problem multiple times but eventually got a “level 3” tech who seemed to get it. My system, too, is showing as off even when the boiler is running, so the history tab is totally inaccurate. He was able to pull up reports looking at a variety of things and suspects it has to do with my system being only 2 wires. He thinks a C wire or a nest power connector would fix the problem. I’ve had my nest for a year and a half with no problem, so it’s not clear to me why this would happen and require that fix now, but he said it could be a variety of things, including the age of the boiler. 

I am monitoring today and tomorrow to see if the issue persists before I do anything. 

[RayC]

Many thanks for responding. My issue has persisted for several days. I too wonder why it should suddenly need a different wiring when it has worked well since installation for a couple of years; something changed at the software end seems more likely or just total failure? Of course if Google Nest supplied a new thermostat that would be a great test, but although this used to be done quickly according to some YouTube advice, it has not been offered yet. Clearly I can only arrange to check out wiring with an electrician or use the plumber who originally fitted the whole system and is familiar with the set-up but fitted it as per instructions and does not claim to be a tech expert. This is not a quick fix.

[DL1221]

So far, I haven't seen the issue come up again today in my home. One of the troubleshooting steps the level 3 tech had me do was reverse my W1 and Rh wires -- he said it's perfectly safe to do so on a two-wire system like mine, and it might help us figure out what is going on. Not sure if that's a long-term fix, or just coincidental that, to date, we haven't had the issue occur again today. (And, for the record, not suggesting it would be a safe thing to do on your system without knowing your system! Proceed at your own risk!)

[RayC]

My plumber solved it. Faulty motor spring mechanism on valve, so it stayed open even when told to shut off. Nest controls working fine, so spent longer than I should to get to that end. It seems to be a common problem and it would be good if Chat lines were able to suggest that sooner as a possibility.

[Coachgsboo]

I’m having the same problem. I haven’t had any problems with our nest but now it runs constantly on won’t shut unless I manually shut down the actual unit. I set the temperature to 63 and it’s now 68 in my house and still won’t shut off 🤨 I have now turned it to heat/cool, so now I’m hot then cold hot then cold . So frustrated!!! Now my a/c guy is coming to look at it and I think plans to just put my old thermostat back on. He hates the nest 😫

[Multipass123]

We have two Nest thermostats and one has this exact issue - once it reaches target temperature it doesn't shut off the heating, which happens I'd say about 40% of the time. The other never has this problem. 

I came up with this 'hack' where if it doesn't shut off, I scroll past the current temperature to turn on the heating on the thermostat again, then hold for maybe 1-2 seconds and turn it back down. Most of the time this trick turns off the heating and I have no idea why. I've had an electrician look at it already and he said he doesn't know what's up. 

Sounds like the issue could be with the valve, so next step is to get a plumber in to look at it again. 

[BigDog]

It worked! Thank you!!!

[yusa]

Thanks! so glad it worked for me too! 

[gmb57]

Hey MuliPass, mine does exactly the same as yours, worked perfectly for around 4 years, but now seems not to turn off the heating, but your "hack" seems to work.  Did you get a resolution?

[Scudpower]

Thank you, this worked for me too. Although it is distressing reading all the above that a thermostat I have just had installed has this issue with little interest from Google to resolve in a timely manner 😞 thanks so much for the hack it worked for me using the app which is super handy now I know! 🙂

[Metuca]

I have the same issue. The boiler will not turn off even if the temperature is reached at the thermostat. We've changed the valve but it still does the same.now I have to keep heating off as I have no idea what to do.i don't want to get another nest as this is not even 1 year old.:(

[SRW55]

Has anyone found an answer to this problem.  I had a brand new heat/cool system installed today and a brand new Nest thermostat installed with it.  Everything seemed fine initially, but after a few hours I noticed the house was very warm and the system didn't shut off at 68 degrees and the house was at 87 degrees.

[KN0105]

Our "fix" for this is to manually shut off our furnace in the basement via a switch. I then reset the Nest thermostat. Once it is finished restarting, I go downstairs and flip the furnace back on. It fired back up for a minute to complete it's cycle, and it finally shuts off. It has happened twice in the last couple of months, and I'm constantly worried about it happening when I'm at work. It seems like a software issue, and I plan to get rid of Nest and replace with a regular-ass thermostat when funds allow. (We have a complicated heating/cooling system with heat pump and alternate oil heat and will need a pro to set it up correctly).

[Jb6616]

I fixed the problem by installing the old thermostat i had for 14 years.  

[MattJames]

I have the same issue - and it has lasted for months. The heating comes on fine but won't turn off when it reaches the target temperature, despite the Nest Thermostat and Heatlink thinking that they are working fine. Like others I have resorted to fully shutting down my boiler twice a day. My plumber/ installer is perplexed. The boiler is brand new - installed last year. Based on this thread I will try getting the valve checked. If that doesn't work, the Nest is going in the bin, despite having worked just fine for 3 years previously. 

[MattJames]

Just to let everybody know, my Nest spontaneously started working properly again a few weeks ago. It was nothing to do with the multiple factory resets etc that I tried, and my plumber hadn’t gotten around to fixing the valve. I figured that Google/Nest had applied a remote patch to fix a firmware glitch, but since others still seem to be having the same issue that now seems unlikely. I’ll update if there’s any change.