Vent, Valve & Volt
Heat pump not heating, or blowing cool air

You can fix this

Likely cause: a switch or breaker was off

The outdoor unit and the indoor unit each have power that can be switched off. Once it held after one reset, you should be back in business.

Why this happens

Carrier lists a tripped breaker among the causes of a heat pump not heating, and notes the outdoor unit runs on its own 220 or 240 volt breaker. The disconnect next to the outdoor unit and the switch at the indoor unit can also be left off by accident.

How to fix it

  1. Set the thermostat to Heat and give the system several minutes.
  2. Check the breaker again over the next day.
  3. If it trips a second time, leave it off and call an HVAC technician.
  4. Check the filter while you're there. Trane recommends a new one every 1 to 3 months.

When to stop. A breaker that trips again means an electrical fault. Leave it off and call an HVAC technician.

If this does not fix it, tell the HVAC technician

  • Which switch or breaker was off.
  • Whether it has tripped again since.

Build the full list: what to tell the HVAC technician.

Start this troubleshooter over

References (every fact above comes from one of these pages)
  1. Carrier: Heat pump not heating
  2. Trane: Heat pump not heating

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