Heat pumps are remarkable machines that provide both heating and cooling from a single system. They’re increasingly popular in the Pacific Northwest for their energy efficiency and versatility. But when something goes wrong, it’s not always clear whether you’re dealing with a simple fix or a problem that requires professional attention.
This troubleshooting guide covers the most common heat pump issues, which ones you can safely address yourself, and when it’s time to call in a certified HVAC technician.
Common Heat Pump Problems You Can Fix Yourself
Before calling for service, try these simple troubleshooting steps that resolve many common heat pump issues:
Check the Thermostat Settings
It sounds basic, but incorrect thermostat settings cause a surprising number of service calls. Make sure your thermostat is set to “Heat” in winter and “Cool” in summer (not “Emergency Heat” for normal use). Verify the temperature is set above (heating) or below (cooling) the current room temperature. Replace thermostat batteries if the display is dim or blank.
Inspect and Replace the Air Filter
A clogged air filter is the single most common cause of heat pump problems. It restricts airflow, causing the system to work harder, freeze up, or overheat. Check your filter monthly and replace it every 1-3 months depending on usage, pets, and air quality conditions.
Check the Circuit Breakers
Heat pumps typically have two breakers—one for the indoor air handler and one for the outdoor unit. If either has tripped, reset it. If it trips again immediately, do NOT keep resetting it—this indicates an electrical problem that needs professional attention.
Clear the Outdoor Unit
Remove any leaves, grass clippings, snow, or debris from around the outdoor unit. Maintain at least 2 feet of clearance on all sides for proper airflow. In winter, gently remove any ice buildup (but don’t use sharp tools or hot water on the coils).
Problems That Require Professional Repair
These issues should always be handled by a licensed HVAC technician:
Heat Pump Running Constantly
If your heat pump runs non-stop without reaching the set temperature, it may be low on refrigerant, have a malfunctioning reversing valve, or be undersized for your home. In very cold weather (below 30°F), it’s normal for heat pumps to run longer cycles, but they should still cycle off periodically.
Ice Buildup on the Outdoor Unit
Light frost on the outdoor coil during heating mode is normal—the defrost cycle should clear it automatically every 30-90 minutes. However, heavy ice buildup that persists indicates problems with the defrost control board, defrost timer, reversing valve, or low refrigerant levels. Operating a heavily iced unit can damage the compressor.
Heat Pump Blowing Cold Air in Heat Mode
If your heat pump blows cold air when set to heat, possible causes include a stuck reversing valve, low refrigerant charge, or a malfunctioning defrost cycle. Check your thermostat first—if it’s set correctly and the system is blowing cold air, call a technician.
Refrigerant Leaks
Signs of a refrigerant leak include ice on the refrigerant lines, hissing sounds near the outdoor unit, reduced heating/cooling performance, and higher-than-normal energy bills. Refrigerant handling requires EPA Section 608 certification—never attempt to recharge refrigerant yourself.
Preventive Maintenance: Avoiding Problems Before They Start
The best way to avoid heat pump problems is regular preventive maintenance. A professional tune-up twice a year (spring and fall) keeps your system running efficiently and catches small issues before they become expensive repairs. Here’s a basic maintenance schedule:
- Monthly: Check and replace air filters, clear debris from outdoor unit
- Quarterly: Clean supply and return vents, check thermostat operation
- Bi-annually (professional): Complete system inspection including refrigerant levels, electrical connections, coil cleaning, and defrost cycle testing
- Annually: Clean condensate drain line, inspect ductwork for leaks
Most heat pumps last 12-15 years with proper maintenance, and well-maintained systems can provide efficient, reliable comfort for even longer.
Understanding Heat Pump Efficiency Ratings
When shopping for a new heat pump or evaluating your current system’s performance, understanding efficiency ratings helps you make informed decisions:
- SEER2 (Seasonal Energy Efficiency Ratio 2) — Measures cooling efficiency. Higher numbers mean better efficiency. The minimum for our region is 14.3 SEER2, but we recommend 16+ for optimal savings.
- HSPF2 (Heating Seasonal Performance Factor 2) — Measures heating efficiency. Look for 8.5+ HSPF2 for Pacific Northwest climate conditions.
- COP (Coefficient of Performance) — The ratio of heat output to energy input. A COP of 3.0 means the system produces 3 units of heat for every 1 unit of electricity consumed.
A well-maintained heat pump operating at peak efficiency can reduce your heating costs by 30–50% compared to electric resistance heating. If your system’s efficiency has noticeably declined, it may be time for a professional tune-up or, if the system is over 12–15 years old, a replacement with a modern high-efficiency model.
Need Professional Heat Pump Service?
If your heat pump troubleshooting hasn’t resolved the issue, it’s time to call in the experts. Sarkinen Heating & Cooling provides comprehensive heat pump services including repair, maintenance, and new installations throughout the Portland Metro area and SW Washington. Our technicians are factory-trained on all major brands including Mitsubishi, Daikin, and Fujitsu. We also help you take advantage of Energy Trust of Oregon and Clark Public Utilities rebates for heating solutions upgrades. Call (360) 940-0305 or request a free estimate online.