Heat pump system does not engage auxiliary or emergency heat when needed

Safety: Turn off power to all HVAC equipment before accessing wiring or electric heat strips.

• Verify system type: In the Honeywell Home thermostat installer setup, confirm the system is configured as a heat pump with auxiliary heat and that the correct number of heat stages is selected.
• Check W2/Aux wiring: Ensure the Aux/W2 terminal at the thermostat and the corresponding terminal at the air handler or furnace are securely wired.
• Test emergency heat mode: Switch the thermostat to Emergency Heat. If no heat is produced, the auxiliary heat source (electric strips or furnace) may have a control or power issue.
• Inspect equipment relays and breakers: For electric heat, check dedicated breakers and any contactors or relays controlling the heat strips. Reset tripped breakers and replace failed relays as needed.
• Call a technician: High‑amperage auxiliary heat circuits can be dangerous. If wiring and configuration appear correct but aux heat still fails, have a professional test the thermostat output and heat controls.