Amazon Smart Thermostat Doesn't Switch On Heat

If your Thermostat doesn’t switch on heat, or heats above the set temperature, start by checking the wiring.

Note: If you're not comfortable working with electrical wiring on your home heating and cooling system, contact an HVAC service company.

Important: Always switch off power to the heating and cooling system (HVAC) before starting work on the Thermostat or HVAC. Switch off power at the breaker box or using the system's primary power switch. Verify that power is off before removing the device faceplate. You can verify that the power is off by confirming that the screen is blank. Don’t touch any exposed wire ends.

To troubleshoot your Amazon Smart Thermostat:

  1. Confirm the system type.
    1. Press the mode button until the flame icon illuminates. Then press the up arrow until the temperature is 1 degree or 2 degrees above the current display temperature.
    2. Once the heating system is running, go back outside to the outdoor unit and check if this unit is on and blowing air. If it's running and blowing air, the system is a heat pump. Otherwise, it's a conventional system.
  2. Remove Thermostat faceplate and check the physical R and RC wires.
    1. If there’s only one wire, it goes to the R terminal with the jumper in the up position.
    2. For both R and RC wires, put the jumper in the down position. Then the RC wire goes into the RC terminal and the R into the R terminal.
    3. In a conventional system, check the W, R, Y, G, and C wires are connected to the correct device terminals.
    4. In a heat pump system, check the Y and O/B and R, G, C wires are connected to the correct device terminals. For systems with a heat pump, there should be no W wire in the W terminal.
    5. Move the wires to the correct terminals as necessary.
    6. If you moved any wires, Reset Your Amazon Smart Thermostat and Set Up Your Amazon Smart Thermostat again. Confirm the W or Y and O/B connection.
  3. Check the Alexa app for the correct wire connections. To check the wiring in the Alexa app, go to Settings. Then go to Thermostat Configurations and select Connected wire map.
    1. In a conventional system, there’s a W connection in addition to R, Y, G, C.
    2. In a heat pump system, there’s a Y and O/B connection in addition to R, G, C.
    3. For alternate wiring terminals, see Amazon Smart Thermostat wire terminals.
    4. If you moved any wires, Reset Your Amazon Smart Thermostat and Set Up Your Amazon Smart Thermostat again.
  4. Set your Thermostat to Heat mode in the Alexa app.
  5. Set the temperature higher than the current temperature on the display, and see if your outdoor HVAC unit turns on.
  6. If you still can't resolve the issue, contact customer support.

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