Tempstar Indoor/Outdoor Mismatch or Reversing Valve Stuck (heat pump models)

Tempstar air conditioner blows warm air from vents even though outdoor unit is running

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Reversing valve stuck in heating mode, Low refrigerant charge, Faulty thermostat wiring (Y/O/B), Failed reversing valve coil

Safety first: Turn OFF power before accessing wiring.

Steps:

1. Verify thermostat mode: Ensure it is set to COOL, not HEAT or EMERGENCY HEAT.
2. Check wiring at thermostat: Confirm the O/B reversing valve wire is connected correctly per Tempstar wiring diagram.
3. Observe outdoor unit: On a heat pump, listen for changeover when switching between heat and cool; if no change, the reversing valve may be stuck.
4. Call a technician: Reversing valve and refrigerant issues require professional service.

Hard 4/5

Reversing Valve Coil

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