Why Is My Heat Pump Electric Bill So High — Causes and Solutions
Published: July 15, 2026 — BC Wide Home Services Ltd, doing business as BC Wide Heating & Air Conditioning — Greater Vancouver, BC
Check If Auxiliary Heat Is Running
The most common cause of high heat pump electric bills is the auxiliary (backup) electric resistance heat running more than necessary. Auxiliary heat uses 2-3 times more electricity than the heat pump compressor and should only activate during very cold weather or during defrost cycles. Check your thermostat display — if it shows Aux Heat, Emergency Heat, or a similar indicator during normal operation, your heat pump is not providing primary heating. Common causes: the heat pump cannot satisfy the thermostat due to dirty coils, low refrigerant, or an undersized system. The thermostat is programmed to bring on auxiliary heat too aggressively (e.g., when set temperature is more than 2 degrees above room temperature). The outdoor unit has failed and the system is running entirely on backup heat without you realizing it.
Dirty Coils and Filters
A dirty outdoor coil cannot effectively extract heat from the air, reducing the heat pump capacity and efficiency. When the reduced capacity cannot meet the heating demand, the auxiliary heat activates to compensate. An indoor air filter clogged with dust restricts airflow across the indoor coil, reducing heat transfer to your home. Both conditions force the system to run longer and use more electricity for the same amount of delivered heat. Clean or replace filters monthly during heavy heating seasons. Have the outdoor coil professionally cleaned annually. After cleaning, monitor your next electric bill — a 15-25% reduction is common when dirty coils were the cause.
Thermostat Programming Issues
Using large temperature setbacks (lowering the thermostat by more than 3 degrees Celsius at night or when away) can actually increase electricity usage with a heat pump. When the thermostat calls for a large temperature recovery in the morning, the auxiliary heat activates to speed up the warm-up. A heat pump is most efficient maintaining a steady temperature or using small setbacks of 1-2 degrees. Program your thermostat to maintain a consistent temperature during heating season. If you have a smart thermostat, check the settings for auxiliary heat lockout temperature — set it to -5 degrees Celsius or lower for cold-climate heat pumps in Vancouver, meaning the auxiliary heat will not activate unless outdoor temperatures drop below that threshold.
Refrigerant Leak or Mechanical Issues
A low refrigerant charge reduces both heating capacity and efficiency. The compressor runs longer to deliver the same amount of heat. If you have noticed a gradual decline in heating performance alongside higher bills, a refrigerant leak is likely. A failing compressor draws higher amps while delivering less heating output. Outdoor fan motor issues reduce heat extraction from outside air. Any of these mechanical issues require professional diagnosis. Compare your electric bills to the same months from the previous year using BC Hydro online account tools. A 30% or greater increase without changes in usage patterns strongly suggests equipment issues. Call for professional service — continuing to operate a malfunctioning heat pump can cause further damage and even higher bills.