Why Is My Heat Pump Not Turning On? Causes and Solutions

If your heat pump is not turning on, don’t panic. You may be able to fix the problem yourself if it’s something simple. But be prepared to call for heat pump repair. Below, we’ve listed some of the most common causes of a heat pump not turning on, and what to do about it.

Let’s get started.

With any heat pump troubleshooting, the first place to start is your thermostat. Check to make sure it is set to Heat or Cool. Incorrect thermostat settings are one of the most common reasons for a heating and cooling system that won’t turn on.

Does the thermostat have power? If a digital screen is blank, the thermostat doesn’t have power, which means it can’t signal your electric heat pump to turn on. Replace the batteries if applicable. Have an HVAC technician check the thermostat wiring if it’s a wired unit. If the thermostat is older, it may have failed.

If you just installed a new thermostat, it’s possible you did it incorrectly, or that the thermostat you bought isn’t compatible with heat pumps. Not all of them are.

If the issue is a failed thermostat, you’ll need to plan on thermostat replacement. Be sure to get a thermostat that is compatible with heat pumps (not all of them are) and professional installation for optimal performance.

If the thermostat isn’t to blame, low airflow could be. Your heat pump system needs adequate airflow to operate properly. A clogged, dirty air filter or blockage in the outdoor unit can cause the heat pump to overheat and shut down. 

Check the air filter and change it if it’s dirty. Use our air filter maintenance guide for tips. Make sure furniture or curtains are not blocking the return air vents. 

In addition, go outside to the heat pump and make sure it’s clear of debris. If there are leaves or twigs on top, clear them away. Do the same thing with snow. Make sure there is at least one to two feet of clearance around the unit. Trim back shrubs and plants as needed.

If the heat pump is not turning on outside, make sure there is power to the heat pump. Check the circuit breaker box and look for tripped circuit breakers. If the breaker for the heat pump is tripped, call for HVAC service. There may be a problem with the unit that caused the breaker to trip. Resetting the circuit breaker and restarting the unit could cause further damage. 

A heat pump capacitor gives the compressor motor and fan motor a little jolt of electricity to help the unit start. Specifically, the start capacitor does this. Your heat pump may have a separate start capacitor and run capacitor, or both may be contained in one unit. 

If the capacitor has failed, the heat pump may make a clicking sound but fail to start. You’ll need to call an HVAC company for capacitor replacement. 

Finally, if the first four issues are not the problem, it could be that your heat pump compressor failed. If an HVAC technician has ruled out everything else and the heat pump compressor is not turning on, you may have a failed compressor. If the HVAC technician determines that you have a failed compressor, you can opt for compressor replacement. 

However, if your HVAC system is more than 10 years old and you’ve had an increasing number of repairs, it may be time to consider heat pump replacement. Check out our blog on average heat pump repair costs as well as our  Repair or Replace Guide for help making this important decision.

Make it a point to perform regular heat pump maintenance. Your heat pump works hard to heat or cool your home all year long. Practice regular air filter maintenance to prevent problems and help your heat pump operate efficiently. In general, you need to change the air filter every 1-3 months. 

Protect your investment and your comfort and schedule heat pump service for each fall and each spring. Be sure to hire an HVAC company with expertise in heat pumps. If the unit is still under warranty, try and use the HVAC contractor who installed it. 

Opting into Trane Diagnostics via the Trane Home App allows your dealer to monitor your heat pump system remotely. How? Your Trane smart thermostat sends data in real-time to your dealer, alerting them to maintenance needs or system malfunctions. This may be before you even realize there’s a problem and protects you even while you’re on vacation.

If they detect a problem they will run heat pump troubleshooting tests to narrow down or even pinpoint the problem. Sometimes, they can fix the problem remotely. In this situation, they would ask for one-time dealer remote access (DRA). 

If they need to schedule on-site heat pump repair services, the HVAC technician will arrive at your home with the knowledge gained from remote access. This results in a shorter service call and ensures the technician has the right heat pump replacement parts. 

Anne Fonda, Content Writer at Trane Technologies

A Content Writer with Trane Technologies, Anne Fonda researches topics and writes for Trane® and associated residential HVAC brands. She works in collaboration with Trane Technologies subject matter experts, offering easy-to-understand, informative content on complex topics. Her goal is to help consumers make informed decisions on the products and services they need.

She has written for HVAC and other service provider websites for over 16 years. Before transitioning to web content writing, Anne had a 14-year stint as an award-winning journalist. She graduated cum laude from the University of Missouri-Columbia School of Journalism. When she’s not working, Anne enjoys playing word games, reading, gardening, spending time with family, and visiting gardens and museums.

Expert review by Mark Woodruff, Senior Product Manager, Ducted Outdoor

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