Thermostat shows E10 and indicates high internal temperature, may shut down temporarily

Safety first: Turn off power to the HVAC system if you smell burning or see smoke from the thermostat.

Steps to resolve E10 overheat:

• 1. Check location: Verify the thermostat is not installed above a lamp, TV, or other heat source. If it is, plan to relocate it to an interior wall away from direct heat and sunlight.
• 2. Inspect nearby vents: Ensure a supply register is not blowing directly on the thermostat. Redirect the vent or adjust louvers to prevent hot air from hitting the thermostat.
• 3. Check wall cavity: Remove the thermostat and feel inside the wall opening. If the cavity is very warm (e.g., due to a flue or hot water pipe), add an insulating foam gasket behind the sub-base or relocate the thermostat.
• 4. Look for damage: Inspect the back of the thermostat for discoloration or burn marks. If present, do not reuse the thermostat.
• 5. Relocate or replace: If E10 recurs despite environmental corrections, replace the thermostat and consider relocating it to a cooler, representative location in the home.