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 

[Zsys]

I am using nest since 2019 and had issue when software was updated in Dec 2019 which was solved when i get the replacement nest as it was not connecting to heat link.

Now today i saw my nest was showing error once and then it switched on but my boiler continously on. Is there any solution yet as nest is not interacting with heat link seems software update issue.

[KN0105]

Our HVAC guy is already ordering me a new Honeywell thermostat because I'm 1000% over the Nest. It happened again a couple of weeks ago, and I'm done with constantly worrying about coming home from work to my house being 85 degrees. He said he has seen this and plenty of other issues with Nest, and he always tries to steer people away from even bothering with them. It's one thing when your smartphone glitches, but I'm done dealing with it affecting the entire functionality of my HVAC system. 

[Nilosx123]

I came home and the temperature was over 30degrees. I’ve since turned off the boiler completely and then turned it back on and it started tk heat up again. No idea what to do!!!

[SRW55]

Seems to be a common problem with the thermostat from what I have read and no definitive answer. Some people have recommended switching to the Eccobee thermostat instead. Not sure what I am doing, but I do know the Nest is being taken off and returned.

[Adysprake]

Hi,

I’ve got the same problem, started yesterday as I returned home to find the house like a sweat box. Turned the heating down and opened door to cool down thinking it was outside temperature heating the house out (I’m in the UK it’s not that hot)! Woke up at 4am to find house red hot and unable to switch off heat. Will call out the guy who fitted it today to see if he can fix the problem.

[Vishalsharma81]

Hi. Any luck?

[PaulHinks]

I have this exact problem ... can anyone offer any help. I've performed a factory reset on the HEAT Link device but the fault is still there. The Nest Thermostat and Heat Link have been installed for approx. 2 yrs.

[Airshod]

I also woke up sweating and realised the heating was on, even though the 3rd generation controller was off. After some investigation, I found that towels in the airing cupboard were pushing against the round  override button on the white heat link box at the back of the cupboard! 

[cenmul]

I have the same problem. I think I solved it. Reset the thermostat. You can do a full reset without losing data saved. Then reset the main nest control box. Mine was in the airing cupboard. Keep your finger on the middle nest button for around 20 secs. I bet all your green lights are lit up with the thermostat turned down and hot water off. Keep button pressed until a solid blue light stays on. Now try your heating or hot water through the app or thermostat. Hopefully you will get that nice click from the control box. Good luck. 

[dshamilt]

I think i've solved my issue.   My heatlink had three lights on.  Which looks like some sort of override to turn the boiler on manually.

I pressed the big button in the middle,  so only one light appears.

Boiler now seems to be responding to my thermostat 😳

(if that is my issue, i think i must have just knocked it tidying up)

[Paddock328]

Nest fitted and working fine for around 4 years. Only one hitch with hot water schedule prior. I’m reporting back because most people don’t advise when they sort their own problem and because one of the above posts helped me. 

Same problem. Went away for a week. Switched heating off on app and switched hot water schedule off. Boosted hot water on return, came back to hot water. All good. 

Still wanted heating off and had not yet switched hot water back on to schedule. But transpired that heating was on but Nest said it was off. History showed no usage. 

Resolved by: restarted thermostat. Pressed and held circular button on Nest control box as said above for approximately 30 seconds three green vertical lights, one more single press and it was back to a single light. Switched hot water back to schedule and it now all works as it should. 

Restarting hot water schedule on its own made no difference. 

[SirN00balot]

Also my issue. The electrician that replaced the HeatLink must have left the override on 😤

[GeeDub]

the first time I set my nest to heat (came with the house I just moved into, so I have no way to activate the app) I set it to 68 in the morning it was up to 86 even though it showed to **bleep** off at 68, then I shut it off thinking that would solve the problem, then about an hour later it was up to 91° so I had to shut it off at the breaker box.  o think tomorrow I am just going to go buy a conventional thermostat like a Honeywell.

[Samwise33]

I am also having this exact issue. Installed new Nest on a heat pump that was working fine with the old thermostat. Now heating continuously and can’t get it to stop. Trying soft and hard/factory resets. 

[Samwise33]

Update for those who also find this thread:

- I contacted Google Nest customer support directly and, after we tested that the cooling system worked fine but the heating did not, the tech suggested that I switch the O/B wire to the W1 input because he suspected that we had separate heating and cooling systems.  This appears to have solved the problem.

(Note that in my case we had just upgraded to a Nest from an old thermostat, so it was clear we had none of the mechanical issues that other posters had identified and also did not have the "it was working for months/years and then suddenly stopped").

Apparently, the O/B wire goes in O/B if you have a single heating/cooling heat pump system, but if they are separate, you need to route to W1 - even if in your old thermostat the wire was connected to O/B (as mine was).

- I had previously tried soft/standard reset and factory reset, both of which did turn off the heat when applied, but did not rectify the actual problem (heat started and continued even after reaching a set temperature for the house).

- If you are having this problem, one useful test to try is to see whether the cooling system works as designed - if so, it may be a specific issue with the O/B wire. 

[Thosgreaves]

This sounds like it could be a solution to my exact same problem. Google has had me disconnect the thermostat from the Wi-Fi and auto sensing and all schedules and is making me wait 24 hours til they’ll listen to me tell them it’s not fixed. I don’t really want to wait but I’ve thought from the beginning it may be a wiring problem. How many wires does yours have? (Does that matter?)

[Samwise33]

I had four wires - yellow, green, red, and white. I moved the white wire from O/B to W1 and that was what fixed it.  There are a bunch of websites out there explaining what each wire does, though it's painful to try to figure it all out.  Good luck!

[alemarcohen]

I have the same problem discussed in this thread. Room thermostat (19C) is set BELOW room temperature (25C), however Nest is still sending signal for my electrical hot water boiler to heat the radiators. After spending more than an hour with Nest technical support and trying all possible options, they replied that connecting a C cable to the unit could fix the problem. I'm surprised because this hadn't been a problem in the past... at least I got someone on the phone!!! I'll try the c cable trick and follow up

[Oison365]

Same problem. Had heating mode on manual. Turned it off manual when I went to bed. Thermostat was showing heat was off. Control was showing heat was off manual mode. Woke early with the room sweltering. Rads were hot. Thermostat still showing as off but showing a temperature of 20C with an outside temperature of 7C. Any ideas?

[Noel121]

Similar/same issues. Nest thermostat and heating system has been working fine until now. Thermostat is set to a schedule and readings match the input. However, despite what the display says the heating remains on! This has only just started as everything was fine until a few days ago. Heating on permanently which is a huge cost in UK at the moment! Have rebooted the thermostat and all connected to Wi-Fi but still heating won’t turn off despite display set to 9 degrees. Any solutions?

[cenmul]

Have you tried resetting the main nest white box. Keep the middle button pressed for over 10 secs 

[Longpigs]

Same for me in the UK. I came down this morning and thought it seemed warm. A few hours later, the thermostat was still saying below the room temperature, but the UFH was definitely on. I've checked the manifold and the boiler and both are on so something isn't right. 

[Noel121]

So, I have since discovered that my boiler , which is situated in the garage, has a safety feature that keeps the boiler running if we get cold weather, (anything below 4 degrees to prevent external pipes freezing ). Hence the heating staying on. Unfortunately it has been installed incorrectly so feeding hot water back into house and keeping radiators on rather than just the external pipes.

Might be worth checking this if your nest thermometer is saying heating off but is still obviously on! 

[Noel121]

Footnote to the above, since weather has got warmer the heating is back to normal, so definitely not an issue with the thermostat. 

[spectra]

Ours was working fine until the nest controller lost power.  Now it acts erratically.  It wasn't a surge.  The power strip was shut off where the Nest control was connected.  The furnace never lost power. We thought we had it working properly for a week or so and then it started acting up again. No lost power this time.

[mhulks]

Hi, I was wondering if anyone found a common solution to this? Exact same problem to us. Boiler responds fine to call for HW or CH but cannot switch off. Have reset thermostat & heatlink. As others have said, nest been working fine for a year then out of nowhere this…

[sparra03]

I have exactly the same problem today. The Hive customer service tell me my boiler is faulty which I seriously doubt. How did you resolve your problem ?

[mhulks]

Hi - it was diagnosed by an engineer as a faulty motorised valve. Nothing to do with the nest. The valve head was replaced for about £140 (labour + part).

[whitehouse123]

We are experiencing the boiler won't turn off problem.  Have checked and reset all possible options so left thinking it is the heatlink or a sticky switch - has anyone found a solution?

[66damo66]

Read my latest post👍

[66damo66]

Hi everyone 

I had this problem. But I have remarkably solved it!! I’ve had the google nest since last September. Been working fine since then, then blow me down 2 days ago, I lost all control of my heating . It didn’t matter what temp I turned it down to, it was still kicking in. I did all the resets, moved the thermostat, you name it , I tried it!

Then I had a eureka moment! Attached to my boiler, is a sealed frost stat. This should be set to 5 degrees Celsius, mine was set to 20 degrees C.  I turned it down to 5 degrees, and hey presto, it’s all sorted! This is a frost protection for the boiler, if it drops below 5 degrees, then it kicks in. My boiler was kicking in when it dropped below 20 degrees c, regardless of whatever temp I was asking for. My daily gas usage has dropped by 25% as well. A win win situation.

hope this post helps someone, can’t believe BOXT installed a new boiler, pump, nest thermostat and didn’t check this!!

[66damo66]

Hi everyone 

I had this problem. But I have remarkably solved it!! I’ve had the google nest since last September. Been working fine since then, then blow me down 2 days ago, I lost all control of my heating . It didn’t matter what temp I turned it down to, it was still kicking in. I did all the resets, moved the thermostat, you name it , I tried it!

Then I had a eureka moment! Attached to my boiler, is a sealed frost stat. This should be set to 5 degrees Celsius, mine was set to 20 degrees C.  I turned it down to 5 degrees, and hey presto, it’s all sorted! This is a frost protection for the boiler, if it drops below 5 degrees, then it kicks in. My boiler was kicking in when it dropped below 20 degrees c, regardless of whatever temp I was asking for. My daily gas usage has dropped by 25% as well. A win win situation.

hope this post helps someone, can’t believe BOXT installed a new boiler, pump, nest thermostat and didn’t check this!!

[rek_]

This happened today after having the furnace service / filter changed. I have to shut it off at the power swirly h in the furnace closet so I won’t be able to have it in tonight while I’m sleeping or it will heat to 90 like it did this afternoon - and it’s February so terrible timing

[Fe1]

Had same issue of heating not turning off despite selecting off on thermostat and app. Called the helpline for my Nest Learning thermostat (UK) and the following simple steps resolved the issue for me:

Had to unpair thermostat and Heat Link first by pressing middle button of heat link for 30 seconds. Then light started flashing blue. Take a picture of the 6 digit code below heat link.
Then go back to thermostat and re-link both using wireless option (equipment>heat link...) and entering the 6 digit code.
Once paired head back to boiler. Then "turn on" heaters using the phone app and listen for the click at heat link. Then turn off using app and listen for the click at heat link, as well as the whirring of the motorised valve. Now works fine.

[gmb57]

I had the same issue.  Fixed by fitting a new motorised 3 way valve (well, valve seemed fine, just replaced the motor)  Been working perfectly now for about a month