My furnace blinks code 13

[Mo_A]

Hello, I have installed Nest learning thermostat lately and I have started to notice my furnace goes on lockout every few days, so I would need to turn power off and on again to get it back up and running again. HVAC tech inspected the furnace and didn’t find anything out of the ordinary. Any idea if it is a thermostat-related ? Thanks 

[Markjosephp]

Hello Mo_A,

Thank you for reaching out and sharing your experience with the Nest Learning Thermostat installation. We appreciate your engagement in troubleshooting the issue with your furnace going on lockout and for your proactive approach in having an HVAC technician inspect your furnace. It's essential to rule out any potential issues with the heating system itself.

To further assist you, we suggest checking a few thermostat-related aspects:

1. Ensure that your Nest Thermostat is compatible with your HVAC system. You can share with us your systems make and model.
2. Confirm that the wiring of your thermostat aligns correctly with your HVAC system. Any discrepancies might lead to disruptions in communication between the thermostat and furnace. Post a picture of your old thermostat and Nest Thermostat wiring set up.
3. Did you get the meaning behind the code 13 from your furnace?

I look forward to your response.

Regards,
Mark

[Mo_A]

Thank you Mark for following up.

The furnace is Bryant with model number is 926TB60100V21, manufactured 2021.

Wiring is done correctly and the system is working fine most of the day, yet sometimes it goes on lockout (code 13) and I have to turn the power off and then on again to get it back up and running. When it is in lockout (code 13). I tried uploading pictures to this reply but I couldn't upload pictures to this chat, as I don't have permission to do so for some reason.

Code 13 in the manual says: "Limit Circuit Lockout - Lockout occurs if the limit or flame rollout switch is open longer than 3 minutes or 10 successive limit trips occurred during high-heat. Control will auto-reset after 3 hours"

[Markjosephp]

Hello there,

It sounds like you've done a thorough job checking the wiring and ensuring the correct setup for your furnace. Dealing with intermittent issues can be quite frustrating, but it's great that the system is generally working fine.

Since you've already checked the wiring, it could be helpful to inspect these components for any signs of damage or wear. Additionally, ensure that the air filters are clean and that there are no obstructions in the airflow, as restricted airflow can lead to overheating and trigger the limit switch.

Though the manual mentions that the control will auto-reset after 3 hours, it might be worthwhile to monitor the system during this period to see if it resets on its own. If the problem persists, it could be beneficial to contact a professional HVAC technician to perform a more in-depth diagnosis and address any potential issues with the limit switch or other components.

Best,
Mark