Nest thermostat is not heating consistently.

[nanzpcn]

I could really use some help here.

I have been using the Nest for the past two years and it worked perfectly in both winter and summer. However, it is recently when the Nest stopped working correctly. When it says heat with the orange screen on, the furnace does not ignite the flame, and the fan motor does not run either. When this happens, the inducer fan is running but nothing else. And if I shut down the system and restarted it, it would work sometimes, not every time. The flame would be ignited and then the fan starts running till it reaches the set temperature. 

If I swapped back to my old honeywell thermostat, which does not have any fancy feature, everything would work really well. 

I have a C wire connected to it. 

The most concerning issue is this mostly happens during AM hours. I have disabled the home/away assist, learning, eco and safety, etc all kinds of such features, treating it as a dumb thermostat with a fixed set temp. 

Has anyone encountered the similar issue? It really bothers me.

[sicsacol]

Hi @nanzpcn,

Thanks for reaching out. I'm sorry to hear the heating option on your system isn't working as expected on your Nest thermostat. Don't worry, let's work together to figure out the issue you're experiencing. To help with that, I have a few questions for you:

• What type of Nest thermostat do you have?
• When did the issue start?
• Are there any error messages? If so, what are they exactly?
• What kind of HVAC system do you have?
• When was the last maintenance check for your HVAC system?
• Does the issue happen on heating only, cooling only, or both?

Please let me know the answers to these questions, and I'll be happy to help you further.

Cheers,
Jonathan

[Ram_nestuser]

I also see more or less the same issue stated above, mine switches to eco during night and wouldn't heat up even if temp drops below eco temp or switch back to comfort temp in early mornings but still wouldn't heat. Im able to recover by software turning off and back to heat, mostly works in a single try some times multiple.

Issue occured 2-3 weeks back I tried factory reset but didn't help 

[sicsacol]

Hi @Ram_nestuser,

Thanks for posting in the community forum. I'm sorry to hear you're experiencing unexpected behavior with your Nest thermostat. No worries, I'm here to help.

Please answer the questions that are in the previous post and let me know if you tried any other troubleshooting steps besides restarting the thermostat. 

Any additional details you can provide will be helpful.

Sincerely,
Jonathan