If your heat pump is leaving you cold, you may wonder what’s wrong and whether the issue is serious. As it turns out, this common problem can have many causes. Some of these issues are easy to address, while others require professional repair.
Heat pumps are popular with Florida residents because they’re well-suited to the state’s warm climate. These systems work differently than furnaces and need specialized care when things go wrong. Below, we’ll explore eight reasons your heat pump may not warm the air when it’s in heating mode.
Quick Takeaways
When heat pumps don’t warm your house, thermostat settings, airflow issues, or outdoor unit problems are often to blame.- Dirty air filters are one of the most common causes of underperformance.
- It can be normal for heat pumps to temporarily blow cool air during the defrost cycle.
- Ice buildup on the outdoor unit is a common reason for heating failure.
- Refrigerant leaks and reversing valve issues require professional repair.
- If your heat pump runs constantly but your home feels cold, your unit needs service.
- Florida’s humid climate can create airflow problems that affect heating performance.
How a Heat Pump Produces Heat (And Why It Sometimes Feels Different Than a Furnace)
Heat pumps and furnaces add warmth to your house, but they don’t work the same way. Furnaces burn fuel or use a hot element to generate heat, while heat pumps use an outdoor compressor unit to extract heat from the air and transfer it into your house. Both types of heaters will circulate warm air throughout your home via ductwork.
While furnaces only provide warmth, heat pumps can also cool your home using their reversing valve to switch the flow of refrigerant through their coils. This allows your heat pump to extract heat from your indoor air, as if it were a standard AC unit. If you have a furnace, you also need to have a separate AC for summertime cooling.
Heat pumps and furnaces don’t just function differently; the warmth they emit may not feel the same. Furnaces produce an intense flow of hot, dry air between 100°F and 130°F for relatively short periods at a time, while heat pumps deliver a continuous supply of warm and sometimes more humid air at a lower temperature between 85°F and 100°F. If you’re used to the hot blast of a furnace, heat pump-generated heat may feel lukewarm by comparison.
Common Reasons Your Heat Pump Is Not Heating
If your heat pump is shut down or blowing cool air, it could be because:
1. Your Thermostat Is Set Incorrectly
If your heat pump isn’t heating, check your thermostat. If it’s set to “Cool,” your heat pump may be releasing warm air outside, and you’ll need to switch the system to “Heat” mode.
If your heat pump is in “Heat” mode but blowing cool air, check the fan setting. If the fan setting is “On,” your heat pump may be blowing while the compressor is inactive, which means the air coming out will feel cool. Setting the fan to “Auto” ensures the heat pump will only blow warm air while the system is active.
If your thermostat is improperly calibrated, the air coming out of your vents may feel unusually cool. Malfunctioning thermostats need to be checked by a professional HVAC technician.
2. You Have a Dirty or Clogged Air Filter
All heat pumps have air filters that capture dust and pollutants so you can breathe in cleaner air. When these filters get clogged or dirty, it can restrict airflow and reduce heat output.
If severely clogged air filters put enough strain on your heat pump, it may overheat and shut down. Cleaning or replacing the filter can often resolve this issue.
3. Your Outdoor Unit Is Frozen
When your heat pump pulls heat out of the air, its copper tubing and condenser coils can freeze during the heat transfer process. If ice builds up on these parts of your outdoor unit, your heat pump won’t function effectively.
While it’s normal for some frost to build up on your heat pump, an excessive amount signals trouble. If setting your heat pump to defrost mode fails to remove the ice, have a professional HVAC technician inspect your unit.
4. Your Defrost Cycle Is Running
Heat pumps have a defrost cycle setting that puts the unit into cooling mode for 5 to 15 minutes. This action sends warm refrigerant through the outdoor unit to melt ice and frost while activating indoor backup heat.
If you feel cool air blowing from your vents while the defrost cycle is running, it could be that the emergency heating system is not producing enough heat to compensate. Once the defrost cycle ends, your heat pump should switch back to heating mode automatically, and you should feel warm air blowing from your vents again.
5. You Have Low Refrigerant Levels
Your heat pump contains refrigerant that absorbs and releases heat during the heat transfer process. If your system develops a leak and its refrigerant levels drop, it won’t produce enough heat to meet your demand.
Seeing a pool of liquid or hearing hissing sounds near your outdoor unit signals that you should schedule a service call with a trusted HVAC technician right away.
6. Your Reversing Valve Is Malfunctioning
A heat pump’s reversing valve allows your unit to switch between heating and cooling modes by controlling the flow of refrigerant. If your heat pump is blowing cool air while it’s in heating mode, your reversing valve might be stuck in the wrong position or failing. To diagnose and fix this problem, you’ll need help from an HVAC specialist.
7. You Have Circuit Breaker Issues
If your heat pump won’t run at all, check its circuit breakers. The outdoor unit should be on its own high-voltage breaker, and the indoor unit should be on a separate breaker at the main panel. If either or both are tripped, try safely resetting the breaker while the system is off, then turn your heat pump back on.
If your heat pump’s breakers are on, check your outdoor unit’s dedicated power disconnect switch, which is usually mounted on an exterior wall of your home. This switch should be in the “On” position, but if it’s not, switch it on, then see if your heat pump starts producing warm air. If the switch is turned on but your heat pump isn’t running, have a technician check the switch for a malfunction.
8. You Have Blower Motor or Airflow Problems
If you have weak or no airflow through your ducts, your heat pump won’t be able to circulate warm air through your house. A malfunctioning blower motor could keep air from flowing over the heat exchanger and cause the system to overheat and shut down.
Your airflow could also be blocked by leaves or debris on your outdoor unit. If clearing away dust and vegetation doesn’t resolve the problem, have an HVAC technician address the issue.
Is It Normal for a Heat Pump to Blow Cool Air?
Although it’s unusual for a heat pump to blow cool air during the cooler seasons, there are times when this behavior is normal:
- During the defrost cycle: A heat pump will blow cool or lukewarm air for five to fifteen minutes during a defrost cycle because the system reverses to cooling mode. This switch moves warm refrigerant through the system’s outside unit, melting frost and ice in the process.
- When outdoor temperatures are low: In below-freezing weather, your heat pump will have a difficult time finding heat in the air outside to pull indoors. If you switch your system to auxiliary or emergency heat, it may take a few minutes for you to notice your house warming up.
Note that heat pumps often normally release lukewarm air (85°F or above), which is cooler than your body temperature and may not feel warm against your skin. If air from the vents actually feels cold without explanation, your heat pump could be malfunctioning.
What You Can Safely Check Before Calling for Repair
When your heat pump is failing to warm your house adequately, there are a few things you can check yourself before calling a pro for help:
- Confirm thermostat settings: Make sure your thermostat is in “Heat” mode, the fan is set to “Auto,” and the temperature is set at or above 68°F.
- Replace the air filter: Installing a new, clean air filter will ensure that heated air can flow through your ducts unrestricted.
- Check your breakers: Make sure your heat pump is getting power; otherwise, it won’t run. If the breakers are off, reset them if you can do so safely.
- Inspect the outdoor unit for debris: If debris on your outdoor unit is blocking airflow, your heat pump may underperform or shut down. Clean off your heat pump and see if the situation improves.
- Ensure your vents are open: If your vents are blocked by furniture or rugs, warm air won’t be able to circulate. Make sure your vents are unobstructed and able to release air into your rooms.
If these simple fixes don’t resolve your issue, your heat pump may have a problem that needs professional attention. Heat pumps are complex machines that require specialized equipment and training to maintain and repair. Tasks that involve electrical work or dealing with refrigerant must be carried out by a licensed HVAC technician.
Signs You Need Professional Heat Pump Repair
If you suspect your heat pump needs professional repair, look for these signs:
- Your system runs constantly
- Ice returns repeatedly
- Loud noises
- No airflow
- Your electric bills spike
- Your home never reaches its set temperature
These problems aren’t normal, and you can’t fix them yourself. If you experience a malfunctioning heat pump, call the pros at One Hour Heating & Air Conditioning of Orlando to repair your unit and restore comfort to your home. Although it can be tempting to wait out the problem, ignoring a non-working heat pump can lead to:
Compressor damage- Worsening refrigerant leaks
- Frozen coils
- Electrical component failures
- Higher repair costs
Resolving your heat pump’s issues when they happen can prevent more extensive and expensive repairs and replacements down the road.
FAQs
At One Hour Heating & Air Conditioning of Orlando, we’re here to keep your heat pump in top condition. Below, we’re answering some of our customers’ most frequently asked questions:
Why is my heat pump running but not heating?
If your heat pump is running but not producing heat, you may have faulty thermostat settings, a dirty air filter, restricted airflow, low refrigerant levels, or a stuck reversing valve. If resetting your thermostat, changing your air filter, and cleaning your outdoor unit don’t resolve your issue, you’ll need to call an HVAC technician for service.
Why is my heat pump blowing cold air instead of warm air?
If your heat pump is blowing cold air in winter, it could be in defrost mode, have a stuck reversing valve, be low on refrigerant, or have a faulty compressor. If your unit continues to blow cold air for more than fifteen minutes or is otherwise behaving abnormally, you should have a technician check it out.
Should I switch to emergency heat?
When your heat pump is blowing cold air, switching to auxiliary or emergency heat is the right thing to do. Activating this backup heat source will keep your home warm, but you should only use it temporarily because this mode uses up to three times more energy to run.
Can low refrigerant cause no heat?
If your heat pump is low on refrigerant, it won’t be able to absorb and transfer heat from the outside air effectively. As a result, your heat pump will release lukewarm or cool air and run inefficiently. Your system may also try to compensate for the lack of refrigerant and cause the coils on your outdoor unit to freeze up.
Does a frozen outdoor unit mean my heat pump is broken?
When your outdoor unit is frozen, the amount of frost or ice on your unit can indicate whether your heat pump is likely to be broken. If your unit has a light coating of frost, it may be functioning normally.
On the other hand, a thick coating of ice on your outdoor unit is usually a sign that your heat pump needs service. frozen after taking these steps, it is likely that it requires service from an HVAC professional.
Schedule Heat Pump Repair With One Hour
When your heat pump isn’t warming your home, waiting to solve the problem can make things worse. At One Hour Heating & Air Conditioning of Orlando, our licensed technicians will inspect your system and resolve any airflow, refrigerant, electrical, and reversing valve issues quickly and accurately.
We serve Orlando, FL, and nearby areas with:
- Heat pump repair
- Refrigerant diagnostics
- Airflow and static pressure testing
- Electrical and reversing valve repairs
- Full system inspections
- And more!
Florida residents know they can trust our team for reliable heat pump services. We’re always on time, or you don’t pay a dime, so book your heat pump repair appointment today!