Thermostat display fogs or shows condensation inside the lens

Safety first: Turn off power to the HVAC system at the breaker before removing the thermostat from the wall.

Steps to address:

• Remove and dry: Gently remove the thermostat and allow it to dry in a warm, dry indoor location for several hours.
• Seal wall opening: Inspect the hole in the wall behind the thermostat. Seal gaps with foam or putty to prevent humid or cold air from entering.
• Check for leaks: Look for signs of water damage or leaks in the wall above or below the thermostat.
• Improve insulation: If mounted on an exterior wall, consider adding insulation behind the thermostat or relocating it to an interior wall.

When to replace: If condensation has caused corrosion or the thermostat malfunctions after drying, replace the thermostat and correct the moisture source.