As fall arrives, heat pump HVAC systems will start to switch gears, giving the cooling cycle a rest as these units are called upon for heating. Over the cooler months, you may experience heat pump problems that can stand in the way of perfect heating for your home. A-1 Mechanical explains how you can troubleshoot some of the most common heat pump problems and get your heating system back up and running again quickly!
What are common heat pump problems & how to troubleshoot them? (HVAC repair service)
- Blowing cold air instead of warm — check that the thermostat is set to Heat, the fan is on Auto, ensure there’s no ice buildup outside, or wait through the defrost cycle.
- Heat pump runs all the time — replace dirty filters, open supply vents/return registers, seal air leaks in ducts or around doors/windows.
Heat pump freezing up — turn off power, melt ice with warm water (never chip it), ensure defrost cycle works properly, clear debris and check gutter drainage.
Troubleshoot When Heat Pump Blows Cold Instead of Heat
Heat pumps should blow warm air through the vents when they run as a heating system in fall, winter, and early spring. If you feel cool air coming from your vents, here are a few things to check before you call for repairs to fix your heat pump. For more details, see why your heat pump is not blowing hot air.
- Make sure the thermostat is set to HEAT, not COOL. If the thermostat is set to COOL mode, the heat pump will run cooling cycles and produce cool air. Settings are sometimes incorrectly changed, causing heat pumps to blow cool air.
- Check the fan settings on the thermostat as well. The fan should be set to AUTO mode, not ON. If the fan is accidentally set to ON, it will blow cool air into the house during times when the heat pump itself is not actively cycling, causing homeowners to think there’s an issue with their heat pump system.
- Make sure there is no ice buildup on the outdoor unit. If there is, follow the directions below to melt ice from your unit.
- The heat pump could be running its defrost cycle when you feel the cool air. The defrost cycle typically runs for about 10 to 15 minutes – wait it out to see if heat returns in the next half hour or so.
Identify Causes of Constant Heat Pump Operation
If it seems like your heat pump is running around the clock, it may seem like there’s an issue to worry about. However, it can be normal for your heat pump to run for long periods – especially if outdoor temperatures are very cold. There are some issues that can contribute to a heat pump running longer than it needs to. Learn more about why your heat pump is not heating effectively:
- Dirty air filters can restrict airflow through the system, forcing your heat pump to run for longer periods to supply the home with enough heating. Check the filter, and replace it with a fresh one if you find the filter is dirty and covered in contaminants.
- Make sure all of the supply vents and return air registers in your home are opened and unblocked. These vents can be accidentally covered by furniture, rugs, and other items, which restricts airflow through the house and forces the heat pump to run longer periods.
- Air leaks in ducts, window frames, door jambs, and other problematic areas throughout the house could cause your home to take on excess cool air. This lowers the temperature in your home, forcing the heat pump to run longer periods to make up the warmth you need. Air sealing and duct sealing can eliminate this issue.
Fix Common Issues Behind Frozen Heat Pumps
This problem is more common in the winter when outdoor temperatures are chilly. The outdoor heat pump unit may show a layer of frost or ice on its exterior, which is normal and is periodically removed through the system’s defrost cycle. If the defrost cycle isn’t removing this frost or outside conditions prevent the heat pump from shedding ice, the system will not work correctly. In some cases, you may also need to explore how to choose a new furnace if your current heating system no longer meets your needs.
If you find a heavy layer of ice atop your outdoor heat pump, notice the coils are completely encased in frost or ice, or the entire outdoor unit has a layer of ice around it, the system will not work correctly and could sustain damage if the ice is left for too long.
- Shut off power to the heat pump at the circuit breaker in the home.
- Use a hose to spray the unit with warm water and melt the ice – do not use objects to chip away ice accumulation as that can damage the heat pump system!
- If temperatures are above freezing, restore power to the heat pump and run it in fan mode to blow warm air through the unit and help melt any remaining ice.
Frozen heat pump problems occur for various reasons, such as low refrigerant, issues with the defrost cycle, and even water leaking onto the unit from a faulty gutter above. Make sure overhead gutters are flowing properly, and remove any debris from around your unit. Replace the air filter with a clean one if it is dirty. If the heat pump continues to freeze, call your HVAC company for repairs.
Contact Us for Professional Heat Pump Repair
If you’ve tried the heat pump troubleshooting tips above yet are no closer to solving your heat pump problems, now is the time to contact a heating professional for help. A-1 Mechanical performs heat pump repair services for homeowners throughout the Grand Rapids and Lansing, Michigan areas. Contact us today to request an appointment for heat pump repair services.
Frequently Asked Questions
Question: What should I do if my heat pump is blowing cold air instead of warm?
Answer: First check that the thermostat is set to HEAT, not COOL. Make sure the fan setting is on AUTO rather than ON. Also verify there’s no ice buildup outside, and know that the defrost cycle can temporarily make the air feel cool.
Question: Why does my heat pump seem to run all the time?
Answer: Possible causes are a dirty air filter, blocked or closed vents, or air leaks around ducts, windows or doors. These reduce heating efficiency and force the heat pump to operate longer to maintain temperature. Fixing airflow and sealing leaks helps.
Question: How can I tell if my heat pump is freezing up, and what should I do?
Answer: If you see heavy frost or ice around the outdoor unit or coils, or if the unit is encased in ice, that indicates a freeze problem. Turn off power, gently melt ice with warm water, make sure gutters and surrounding areas drain properly, and replace dirty filters. If the issue continues, call a technician.
Question: What causes a heat pump to short cycle or turn on and off frequently?
Answer: Short cycling can be caused by a clogged air filter, a thermostat issue, or low refrigerant. These problems prevent the system from completing full heating cycles, leading to inefficiency and wear. Cleaning filters and having a pro check refrigerant levels can help.