Heat pumps are known for exceptional efficiency and the ability to provide both heating and cooling for your home. However, as with all HVAC equipment, problems will inevitably arise and require attention. Here are the 12 most common issues you may face with your heat pump plus some tips for overcoming them.
1. Insufficient Heating or Cooling
One of the most common heat pump issues is insufficient heating on very cold days. A heat pump’s compression process pulls heat from ambient air. If the air is too cold outside, this can take a long time and cause the appliance to work overtime. Because of this, many heat pumps will have a backup furnace for those extra cold days. These are called hybrid systems.
2. System Doesn’t Turn On
The system failing to turn on is another obvious problem and often has a simple cause. Start by checking that your thermostat is set properly and has power. Check the breaker to make sure that the system is receiving power, and then double-check that the power disconnect switch is set to On. Finally, check the safety disconnect by the compressor unit outside. If there doesn’t appear to be a problem with the system’s power supply or the thermostat, ask an HVAC professional to find the underlying cause.
3. Short Cycling
Short cycling occurs when your heat pump terminates a heating or cooling cycle prematurely. This often happens when a sensor, accurately or not, senses a system malfunction or airflow restriction. Start by checking the air filter, ensuring that the compressor unit outside is clear and that all your supply vents are open and have at least a 6-inch clearance above and around them.
If all of that is clean and clear, you may have a sensor that needs replacing. An HVAC technician will test all of these sensors during routine heat pump maintenance, helping to stave off any short cycling issues.
4. Heat Pump Running Constantly
A common call into HVAC companies is that their heat pump seems to be running constantly while in heating mode. In many cases, this is not a problem but is indicative of how the heat pump is designed to work. Rather than pumping out hot air like a furnace, your heat pump collects heat from the air, water, or ground outdoors and concentrates it to produces warm air that slowly raises the indoor temperature when needed. It’s designed to maintain that temperature rather than allowing it to cool and then having to warm it up again.
5. Reduced Airflow
Every HVAC system depends on its ability to move air through the system and then circulate conditioned air around your home. There are times you may notice it feels like less air is coming from the supply vents. This could be a function of a variable-speed fan running at a lower speed. However, it can also indicate a clogged air filter, a problem with the blower motor or a frozen indoor coil.
6. Frozen Coils
Your heat pump coils can freeze, most commonly inside your house during cooling mode and outside your house during heating mode. This happens because the coils get too cold and freeze the moisture it condenses out of the air, which compounds quickly. During heating mode, the outside coil may freeze up when temperatures are frigid. From a function and maintenance perspective, frozen coils can be caused by a refrigerant leak or faulty compressor. A faulty outdoor fan motor can also lead to a frozen coil because it prevents the defrost mode from operating properly.
You can often see the frozen coil by looking at your outdoor unit. The ice is clear if you inspect the protected interior of the unit. If the day is warm or temperate, you can turn off the power to the unit until it defrosts. This may be enough to remedy the issue. If the coils freeze again, call a professional to diagnose the cause.
7. Tripping Breakers
Your heat pump should be on at least one circuit on its own. Some electricians may run two circuits, with one running the compressor and the other running the air handling unit. The breaker connected to the compressor is the more common one to trip because of the amount of draw it has. One trip can happen occasionally because of power surges or excess strain on the circuit. However, if the compressor is malfunctioning, it will cause the breaker to trip repeatedly.
8. Blowing Cold Air During Heating Mode
If you’ve recently converted to a heat pump from a gas furnace, it may feel like the system is blowing cool air. This is because a heat pump has a lower temperature rise than a furnace. However, it may feel like air-conditioned air when the system is in defrost mode. This special mode activates when the system senses either frost or ice on the outdoor coil. The indoor fan may continue running to help circulate warm air over the coils to help accelerate how quickly the coil defrosts. Finally, if the reversing valve gets stuck, it may cause the system to blow cold air rather than warm air.
9. Thermostat Problems
A thermostat is the brain of the heat pump, signaling when to cycle on and off and in which mode. Like all other parts of the system, it’s prone to malfunctioning as it ages and wears. You can expect a modern digital thermostat to have a lifespan of 10 to 15 years. During this time, it may have problems like a faulty sensor or improper settings.
10. Climbing Energy Bills
It’s important to keep an eye on your energy bills, especially comparing your energy usage compared to the same month for the previous year. When you have a drastic increase with a known cause, it could signal a problem with your heat pump. This could range from some kind of airflow restriction, like a clogged air filter, to something more significant, like a faulty compressor.
11. Unusual Sounds
When running normally, a heat pump should make almost no noise. You will probably hear the whir of the circulating fan and single clicks as parts of the heat pump activate. Unusual sounds that you may hear include screeching, grinding, gurgling, hissing or a loud buzzing. These noises can indicate problems like seized ball bearings, broken parts inside the compressor, a refrigerant leak or electrical component problems.
12. Leaking Refrigerant
A heat pump depends on having the proper amount of refrigerant in the system. If there’s a refrigerant leak, it may cause one or both coils to freeze and substantial strain to the compressor, potentially causing it to fail. The easiest way to catch a refrigerant leak is through routine heat pump maintenance during which the technician will test the refrigerant charge.
Precision Heating & Air has been the HVAC service provider of choice for property owners around Dallas for more than 30 years. Our customers depend on our heating repair services, maintenance and installation along with our indoor air quality solutions, duct cleaning and water heater services.
Call to schedule a heat pump maintenance or repair visit with one of our NATE-certified technicians today!
