Hello Lucs888,
I appreciate you reaching out to us about your Nest Thermostat that is not detecting any power. I'd be happy to take a look at this for you.
A connection failure might be in the power terminal and cause the power loss. The following notes may be too much, but they would help us isolate the issue:
- Make sure that the breakers are on.
- The circuit breakers could flip due to a power outage or service done on your electrical appliances.
- If you used your AC recently, check your system's drip pan or drain tubes.
- They might be full of water and have a clog. The system shuts itself off to prevent an overflow of water.
- Inspect your HVAC system's fuse.
- If the fuse seems burned or has discoloration, consider a fuse replacement.
- Check for an energy savings box.
- Some utility companies install boxes that cut off the power during high-demand (peak) times.
- Check the air filter.
- A clog in the air filter can limit how much air flows over the cooling coils. If the clog persists, the cooling coils can freeze and cause the system to shut off.
- When was the thermostat installed?
- Did the issue happen during the installation or after the installation?
- Who installed the thermostat?
- Gather the power readings on your thermostat's equipment settings.
- Share with us a photo of your thermostat's wiring.
I'll look forward to your response.
Regards,
Mark
