Patrick Riley Cooling Heating & Plumbing, LLC | Isley's Home Service
Proudly Serving Greater Phoenix | See our service area
← All help articles

Why Is My Heat Pump Tripping the Breaker?

October 13, 2020

Updated: August 16, 2022

Have you reset your heat pump breaker multiple times because it keeps tripping?

If so, it means there’s an issue that needs to be addressed, such as:

  1. A dirty air filter
  2. A dirty outdoor unit
  3. Low refrigerant
  4. An electrical problem
  5. A compressor problem

We’ll go into more detail about each of the issues below. We’ll also tell you right off the bat that besides changing a dirty filter, you will likely need the assistance of a trained HVAC maintenance technician to fix the rest of the problems listed above.


Want a professional HVAC maintenance technician to repair your heat pump? Our skilled technicians are standing by, ready to help! We service Mesa, Phoenix, Gilbert, and surrounding cities.


Problem #1: A dirty air filter

If your air filter is clogged with dust, it acts as a barrier that prevents air from passing through it. As a result, components in your heat pump such as the fan motor have to work extra hard to pull in a sufficient amount of air to be cooled/heated by the heat pump.

The harder these components have to work, the more power they draw. Eventually, they can draw too much power, which causes the heat pump circuit breaker to trip.

Solution: Check your AC air filter for dirt. If it looks like the one in the image below, replace the AC filter immediately.

Dirty Air Filter

A dirty air filter

If the heat pump continues to trip the breaker after replacing the dirty AC filter, do not keep resetting the breaker. Allowing your heat pump to continue tripping the breaker could damage internal components. Instead, contact a professional HVAC technician for further assistance. You may need an air conditioning repair or replacement.

Problem #2: A dirty outdoor unit

The condenser coils inside the outdoor unit release or absorb heat, depending on whether your heat pump is in cooling or heating mode.

If these condenser coils are dirty the heat pump will struggle to heat or cool your home. Similar to a dirty air filter, important components in your heat pump will work overtime to compensate. The overcompensation causes your heat pump to pull extra power and trip the circuit breaker.

Solution: Have a professional HVAC service technician clean and inspect your outdoor unit and its condenser coils.

Problem #3: Low refrigerant

Your heat pump uses a liquid substance called refrigerant to heat or cool your home. If your heat pump is low on refrigerant (which is usually caused by a leak), then the entire system will struggle to keep your home warm or cool.

To compensate for the lack of refrigerant, your heat pump will work extra hard to meet the desired temperature set at the thermostat. All of this extra stress can cause components to draw too much power, which will trip the breaker.

Solution: Contact an HVAC service professional to inspect your heat pump and measure the refrigerant levels. If your heat pump is low on refrigerant, the HVAC service technician will need to find the source of the leak and repair it.

Problem #4: An electrical issue

Several electrical problems can cause the heat pump breaker to trip, including:

  • A shorted fan motor: An electrical short is when electricity bypasses its normal path. In a fan motor, shorts are often created when the insulation around the wires deteriorates. When this happens, the wires receive more electricity than they are designed to handle causing the circuit breaker to trip.
  • Loose or worn-out wiring: Similar to a shorted fan motor, loose or worn-out wires (which are more common with older heat pumps) can cause the breaker to trip by pulling too much power..
  • A faulty breaker: Breakers can start to malfunction as they age—especially if they have been tripped a lot. This could explain why the heat pump circuit breaker trips constantly.

Solution: Have an HVAC maintenance professional inspect the fan motor and wiring in your heat pump. They will repair or run new wires if necessary. If the HVAC service technician finds the breaker is faulty, they may be able to replace the breaker or refer you to an electrician who can help.

Problem #5: A compressor issue

The compressor is the “heart” of your heat pump, located in the outdoor unit. It circulates refrigerant throughout the heat pump and is essential to the cooling/heating process.


The compressor, located inside the outdoor unit

Because the compressor is such a vital part of your heat pump, it naturally draws a lot of power during normal operation. Compressor-related issues that can cause the breaker to trip include:

  • A hard-starting compressor: As a compressor ages, it may struggle to start when the heat pump turns on. A hard-starting compressor often pulls in too much power for the breaker to accommodate.
  • A grounded compressor: A grounded compressor is when the electrical windings inside the compressor hit the side of the metal casing and create a short, which results in a tripped breaker.
  • A bad capacitor: The capacitor is a part that helps the compressor turn on. When a capacitor starts to go bad, it will struggle to kick-start the compressor. If you hear your outdoor unit trying to start and then the circuit breaker trips, this could be the cause.

Solution: An HVAC service professional will need to inspect the compressor and figure out what’s causing the issue. Some compressor issues can be fixed by a technician but others cannot. The compressor is tightly sealed, which makes it difficult (if not impossible) for a technician to perform repairs in the field. If a repair is not possible, replacing the compressor may be the only option.

The bad news is that replacing a compressor is expensive. The good news is, if your manufacturer warranty is still valid, you may not have to pay for a replacement. The professional you hire to fix your heat pump can help you determine whether your warranty is still valid and if compressor replacement is necessary.

Is your heat pump tripping the breaker? Get a repair from a Phoenix pro.

Our skilled HVAC service technicians can quickly find what’s causing your heat pump to trip the circuit breaker and fix the problem. When you hire Patrick Riley, you can count on exceptional customer service and an air conditioning repair that will be done correctly—the first time.

Learn more about what to expect when you hire our HVAC service technicians by visiting our heat pump repair page.

Related reading

Get 10% off (Up to $150)

Sign up for newsletter
By Ty Lindsay

Ty Lindsay is the Director of Field Operations at Patrick Riley | Isley’s and a 15-year veteran of the plumbing and HVAC trades. In 2010, Ty earned his Journeyman’s plumbing license. He became a Master Plumber five years later and earned his Journeyman HVAC technician’s license that same year. Ty’s breadth of knowledge in plumbing and HVAC includes both residential and commercial work. He’s been a loyal member of the Patrick Riley | Isley’s team since 2016.