Thermostat Troubleshooting
A well-functioning thermostat is crucial for controlling your HVAC system—without it, managing your furnace or air conditioner effectively is nearly impossible. To help you keep this essential device in good working order, our thermostat troubleshooting guide will help you identify and resolve issues quickly and easily.
Thermostat Isn’t Working/Won’t Turn On
- Unit isn’t turned on - Turn on the device.
- Batteries are dead - Add fresh batteries. If needed, refer to our step-by-step guide on how to change thermostat batteries.
- Wiring is faulty - Contact a licensed technician to remedy the issue.
- Installation is improper - Call an authorized technician to solve the problem.
- Safety switch is triggered - Reset the thermostat. If issues persist, seek help from a licensed technician to correct the issue.
- Circuit breaker is off or tripped/fuse is blown - Turn the circuit breaker on. If issues persist, reach out to a licensed electrician for assistance.
Display Is Blank or Blinking
- Batteries are dead - Change the batteries. If necessary, see our article on changing thermostat batteries for instructions.
- Wiring is defective - Schedule a service appointment with an authorized technician.
- Safety switch is triggered - Reset the device. See your user’s manual if you need guidance on how to do so.
Unit Won’t Change Temperature
- Device is locked - Unlock the thermostat. If you’re not sure how to unlock it, check your owner’s manual for directions.
- Auto mode is on - Turn off auto mode.
Ambient Temperature Doesn’t Match Display or Setting
- Thermostat isn’t in a proper location - Relocate the thermostat out of direct sunlight, far from heat sources and out of drafts. Be sure to reach out to an authorized technician to solve the issue.
- Unit is dirty - Clean the device per the instructions in the owner’s manual.
- Electrical connections are corroded - Seek help from a licensed technician to correct the problem.
- Temperature sensors are defective - Call an authorized technician to remedy the issue.
- Installation is incorrect - Contact a licensed technician for assistance.
Furnace or Air Conditioner Isn’t Responding to Thermostat Settings
- Mode is incorrect - Set the unit to “cool” for cooling and “heat” for heating.
- Wiring is faulty - Reach out to an authorized technician to address the issue.
Smart Thermostat Can’t Connect to WiFi
- No Internet connection is present - Contact your service provider to solve the problem.
- Internet connection is weak - Place a WiFi signal booster near the device. If issues continue, call an authorized technician for further assistance.
- Device isn’t compatible with the HVAC system - Contact a licensed technician to address the problem.