High winter electric bill with a heat pump
Heat pumps are efficient, but backup heat strips are not. When the bill jumps, that's usually where the power went.
How backup heat works
Most heat pumps in this area have electric heat strips in the indoor unit. They kick in when it's very cold, during defrost, and when you raise the thermostat by several degrees at once. Strips use a lot more electricity than the heat pump itself.
Habits that run up the bill
- Big setbacks at night followed by a big bump in the morning. The strips do the catching up.
- Leaving the thermostat on "Emergency heat" after using it once.
- A thermostat not set up for a heat pump, which can call for strips too often.
Signs of a real problem
- "Aux heat" shows on the thermostat most of the day, even in mild weather.
- The outdoor unit isn't running when the heat is on, or it's covered in ice.
- Air from the vents is only lukewarm and the house won't reach the setpoint.
Those point to a heat pump that isn't pulling its weight, often from low refrigerant or a failed outdoor part. Fixing it can pay for itself quickly in a cold month.