Common Heat Pump Repairs: What You Need to Know

Heat pumps are an efficient way to keep your home comfortable throughout the year. They work by transferring heat instead of generating it, making them a cost-effective option for both heating and cooling. However, like all HVAC equipment, heat pumps can experience issues that may require repairs over the years. 

HVAC.com walks you through some of the most common heat pump repairs that homeowners deal with, their causes, and tips on how to handle them.

Refrigerant Leaks

Refrigerant cycles through the system to move heat in and out of your home. If your heat pump has a refrigerant leak, it can lead to reduced efficiency, increased energy bills, and potential damage to the unit. Leaks often result from wear and tear on the coils or lines, or from poor installation. Corrosion or physical damage to the system and its refrigerant lines can also lead to leaks.

If you suspect a refrigerant leak, it’s best to call a professional HVAC technician. They can locate the leak, repair it, and recharge the system with the proper amount of refrigerant. Avoid trying to fix this yourself, as improper handling can lead to more significant issues. In fact, HVAC technicians are required to hold an EPA certification for safe refrigerant handling and disposal.

Bad Capacitor

Your heat pump’s capacitor helps start the motor and keep it running – some systems have a single capacitor, while others have separate start and run capacitors. If a capacitor fails, your heat pump may experience starting issues or fail to run altogether. Capacitors can fail due to age, electrical surges, or overheating.

If you notice that your heat pump is struggling to start, making a humming noise, or shutting off unexpectedly, the capacitor might be the issue. It’s best to have an HVAC technician diagnose and replace a faulty capacitor. Attempting to replace a capacitor yourself can be risky and may cause further damage if not done correctly, so don’t try to handle this yourself unless you are comfortable working with electrical systems.

Blown Fuse or Tripped Circuit Breaker

Heat pumps require a steady flow of electricity to operate. A blown fuse or tripped circuit breaker can disrupt this flow, causing the system to shut down or function intermittently. Fuses and circuit breakers can trip due to electrical surges, short circuits, overloading or faulty electrical components.

Resetting the circuit breaker or replacing the fuse might resolve the issue. A blown fuse will have a broken filament or a blackened appearance. Replace the faulty fuse in the outdoor unit with one of the same rating, and make sure it fits securely. If the new fuse blows shortly after installation or the circuit breaker continues to trip, there is likely an underlying electrical issue that requires professional attention. 

Short Cycling

When a heat pump turns on and off more frequently than usual, this is known as short cycling. This rapid cycling can disrupt your home’s comfort and cause the system to work inefficiently. An oversized or undersized heat pump, a faulty thermostat, blocked airflow, refrigerant leaks, or issues with the compressor can cause a heat pump to short cycle.

Troubleshoot short cycling by checking and replacing air filters if they are dirty or clogged. If that doesn’t correct the issue, have a technician perform a thorough diagnostic inspection to identify and repair any issues. If short cycling is due to an incorrectly sized unit, the heat pump will need to be replaced with a unit that’s appropriately sized for your home.

Defrost Cycle Problems

During cold weather, heat pumps run through a defrost cycle to remove ice that may form on the outdoor coil. If this cycle fails, ice can build up which reduces heating efficiency and can lead to system damage. Malfunctioning sensors, faulty defrost controls, or a stuck reversing valve commonly cause the defrost cycle to fail, as well as poor airflow or low refrigerant levels.

If you notice ice buildup on the outdoor unit, check if the defrost cycle is running as it should. If problems persist, consult a professional to diagnose and repair the defrost system. Regular maintenance and inspections can help prevent this issue. 

Noisy Operation

Sudden or persistent noises may come from loose or damaged parts, worn bearings, or foreign objects stuck in the unit. If your heat pump is noisy, inspect the unit for visible signs of damage or debris. Remove any debris you find within the outdoor unit, and tighten any loose parts you find. If the noise continues, contact an HVAC technician to diagnose and address the problem.

Inconsistent Heating or Cooling

Inconsistent heating or cooling can make your home uncomfortable and points to issues with your heat pump’s performance. Uneven airflow, refrigerant issues, or problems with the heat pump’s components are common causes of this issue. Faulty ductwork or improper system sizing can also lead to poor temperature control throughout the home.

To troubleshoot this problem, check your air filters and ductwork for blockages or leaks and verify your thermostat is properly calibrated. If the problem continues, have a professional inspect the heat pump and your home’s heating and cooling needs. Your system may require repairs, or a new heat pump may need to be installed to adequately meet your household’s heating and cooling demands.