Thermostat display shows E2 and temperature reading is inaccurate or system will not run

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

• Step 1 – Reboot the thermostat: Turn off the HVAC breaker for 2–3 minutes, then restore power. Check if E2 clears.
• Step 2 – Inspect for moisture: Remove the thermostat from the wall plate. Look for signs of moisture, condensation, or insect debris inside the thermostat vents or on the circuit board. If present, gently dry with a soft cloth and allow the unit to air dry for several hours before reinstallation.
• Step 3 – Check for contamination: Look for corrosion or dirt bridging small components near the sensor area. Do not scrape aggressively; use a soft brush or compressed air.
• Step 4 – Compare temperature: After reinstalling, compare the thermostat reading to a known accurate thermometer in the same room. If the reading is extreme or E2 returns, the sensor is likely shorted internally.
• Step 5 – Replace thermostat: The internal sensor is typically integrated into the Amana smart thermostat PCB and not field-replaceable. Replace the thermostat with a compatible Amana smart thermostat model.

When to call a professional: If there is visible board damage or you are unsure about moisture damage, have an HVAC technician evaluate and replace the thermostat.