Thermostat shows room temperature much higher or lower than actual, causing discomfort.

Safety: No high-voltage work is required for calibration.

• Step 1 – Check installation location:
  • Ensure thermostat is on an interior wall, away from direct sunlight, drafts, and heat sources.
• Step 2 – Seal wall opening:
  • If there is a large hole behind the thermostat, seal around the cable entry with foam or putty to prevent wall cavity air from affecting readings.
• Step 3 – Compare with reference thermometer:
  • Place a thermometer nearby and wait 20 minutes.
  • Note the difference.
• Step 4 – Adjust calibration:
  • In settings, adjust the Temperature Offset to correct the reading.
• Step 5 – Consider external sensor:
  • If location is problematic, install a Protherm external room sensor and configure the thermostat to use it.