Next heating come on during the night

[Martinbruce1]

My nest heating keeps coming on at random times. Mainly during the middle of the night. 

The app is only connected to my phone, no other sources. 

All the true radiant, auto schedule settings are off. My temp is set to 17deg during the night. 

Yet I wake up at 4am and my room is roasting and my thermostat is at 21/22deg. 

This seems to be costing me more money than just running a normal system. 

[gmelanymelissa]

Hi @Martinbruce1,

Thanks for posting here in the community. I'm sorry to hear your Nest heating keeps coming on randomly. I'm happy to help!

To better understand the situation, I'd like to ask a few questions:

• What type of thermostat do you have?
• Are you located in the European Union or North America?
• If you're in North America, do you have a heat pump or a conventional system?
• Would you mind sharing a picture of your wiring configuration? 
• Do you have a heating-only system or both heating and cooling?
• If you have both systems, does the issue occur with heating only, cooling only, or both?
• Are there any error messages displayed on the thermostat?
• Have you noticed any specific intervals or patterns in these unusual occurrences?
• When was the last maintenance check for your HVAC system?
• Have there been any recent changes or upgrades to your HVAC system? 

In the meantime, let's check this tip:

• Turn off Eco mode: Please disable it. Check out this article for instructions: Set your Nest thermostat to heating, Eco, or off.

Keep me posted.

Best regards,

Melany

[Gareth4]

I also have this problem with the heating coming on around 4am for around an hour on some days not all. I had a Nest thermostat in my previous house for years with no problems at all.

This thermostat is 3rd gen installed in the UK to control my heating only.

I have had no error messages.

The thermostat was purchased in August 2022 and installed by a qualified electrician and worked perfectly for the first 18 months or so. The problem started towards the end of winter , March 2024. When I turned the heating back on in September, the problem was still there. I have reset the thermostat, turned auto schedule to off, turned True radiant off . I have deleted the heat schedule and then re done it.

. Currently, I have to remember to turn the heating off when I go to bed and turn it on when I get up. Is there anything else I can try ?

thank you,

Best regards

[luciaaa]

Hi, @Gareth4,

Thank you so much for reaching out to the community. I’m truly sorry the heating activates at 4 am some days. I understand that this situation is very frustrating. I’m happy to help!

Thank you so much for taking the time to turn off the auto schedule, True Radiant, and for resetting the thermostat.

To effectively troubleshoot, please provide the following information: 

• Do you have more than one thermostat in your home? If so:
  • Do any other thermostats have heating points that could explain the activation?
  • For multiple zones, are only the radiators in a particular zone getting heated?
• Do you have a system or a combi boiler? Is the control On/Off or Opentherm?
• What's the status on the Heat Link's LED light?
• Has there been any recent work done on your thermostat(s) or heating system?
• Have you experienced any recent power outages?

In the meantime, please follow these troubleshooting steps: 

• Disable bacterial prevention by following the instructions in this article: Turn bacterial prevention on or off.
• If the Heat Link is in manual mode, turn it off. You can refer to this article for instructions: Manually control heating when Heat Link is disconnected. 

Please let me know how it goes.

Best regards,

Ana

[Gareth4]

HI Ana,

Thank you for your helpful response.

On working through your suggestions, we have a Combi boiler and after opening the panel there is a further thermostat that I was not aware of. We are in an area where we suffer frequent power outages which would explain why the time  on the alternative thermostat timer was incorrect and would appear to have caused the heating to come on during the night. I have now turned this timer off and am pretty confident that this is the problem so will now leave my Nest thermostat on for the next week to see if this has resolved the issue, but will advise you if I still have the problem.  

Thank you again for your help,

Gareth

[luciaaa]

Hi there, 

Thank you very much for letting me know that you turned off the timer. I hope that in the coming weeks the problem will not repeat.

I would really appreciate it if you could share any updates. I'm here to help.

Best regards,

Ana