Thermostat continue heating after reaching the set temperature

[AlainD1]

I set the temperature to 21 but the system continue to heat up to 25+++ or just stay on, what is the issue?

[maedacortez]

Hi AlainD1,

Thanks for reaching out. I understand that your heating system does not turn off when it reaches the target temperature. I am happy to assist you! Before continuing, I need to ask some questions to better understand the situation.

1. What type of Nest thermostat do you have?

2. When did the issue start?

3. What other strange symptoms have you experienced since the problem started?

4. Are there any error messages? If so, what are they exactly?

5. Is this a new installation?
   Ifyes: Have you checked your Heating, Ventilation, and Air Conditioning (HVAC) system's compatibility with your Nest thermostat through the Compatibility Checker tool?

6. What kind of HVAC system do you have? (Heat pump, conventional system, etc.)

7. Does the issue happen on heating only, cooling only, or both?

8. Could you tell me what the wire labels are that you have connected?

I will be awaiting your response.

Regards,

Manuel