Heat Pump Compressor Not Turning On

image of homeowner adjusting heat pump thermostat since heat pump compressor not turning on

We cannot control the weather, but a heat pump can help us control our indoor environment. If it is too cold, you can use it to warm your home. If it’s too hot, you can tweak the settings to feel cooler. Heat pumps are highly versatile, making them extremely useful in any season. However, what will you do when your heat pump compressor doesn’t turn on? It’s a big issue that needs to be resolved right away to ensure your family’s health and comfort. This article discusses all you need to know about a heat pump compressor not turning on and the common reasons behind it.

Explore Our Home HVAC Services Call To Schedule A Free, In-Home Estimate

Heat Pump Compressor Not Turning On

Heat pumps are complex HVAC systems that consist of many moving components. If a component fails, the heat pump may not work as expected. The problem may be easy to find and resolve sometimes. However, the problem may need the expertise and experience of a licensed HVAC technician at other times. Some of the typical culprits are a faulty thermostat, low refrigerant, frozen outdoor coil, and a power supply issue. All these may be due to underlying causes that require thorough checks to ensure a lasting fix.

Call Today: (732) 741-6300

How a Heat Pump Compressor Works

It will be easier to do troubleshooting when you know how heat pumps work. Overall, it has a design similar to air conditioners. The primary difference is that heat pumps can work in reverse, so they are helpful in any season. Air conditioners and heat pumps are electricity-powered and use refrigerants for heat transfer. The compressor controls the coolant’s movement and consumes the highest amount of energy, among other parts. A blower pushes air through the evaporator coils to change the indoor temperature. Another blower forces air through condenser coils outdoors.


Why A Heat Pump Refuses to Turn On

Here are several possible causes the heat pump isn’t working as it should:

An Aging Heat Pump Thermostat

The thermostat controls the heat pump. It tells when the system needs to run or stop per the sensor readings. It pushes the heat pump to run in cycles until the indoor temperature matches the user’s settings. Once the goal is achieved, the heat pump will stop, monitor the ambient temperature, and restart the cycle when needed. Old thermostats may not work as seamlessly due to the grime and dust on the sensors. Normal wear and tear also impact its accuracy. Cleaning may help but getting a thermostat replacement may be needed.

Spent Thermostat Batteries

corroded old thermostat batteries

The thermostat may be relatively new and accurate. However, it may not be getting enough power to start. A thermostat that can’t turn on means the heat pump cannot receive the signal on when to start its operation. Check the thermostat’s batteries as they may no longer have enough charge. Change them with new ones to see if that gets the thermostat going. If the display flashes any numbers, the problem may be resolved.

Proximity to Heat Sources

After cleaning the thermostat and changing the batteries but the problem persists, it may be because the thermostat is near a heat source. This means that the thermostat gets unusually high sensor readings because it is close to a source of heat. Examples of heat sources are an open window or a space heater. If so, close the window and ensure direct sunlight doesn’t hit the thermostat. Move the heater somewhere else as well. These steps should allow your thermostat to have more accurate temperature readings.

Learn More About Our Heat Pump System Services Call To Schedule A Free Estimate

The Heat Pump Power Connection

Check if your heat pump is plugged in. Your heat pump should have its own circuit breaker to isolate it from the rest of your home’s circuitry. Check if it is set to ON. Otherwise, switch it and see if that solves the issue. Check for a tripped breaker or a blown fuse as well. Reset the breaker and replace the fuse to resolve the issue.

Dirty Heat Pump Air Filters

dirty heat pump air filter

A system that runs but trips repeatedly likely has another problem. For instance, the heat pump may be drawing more power and working harder than usual. The breaker may not be able to handle it, so it constantly trips when you start your heat pump. One of the possible causes is dirty air filters. These keep sufficient airflow from passing through, forcing the system to overcompensate. Inspect the filters to see if they are dirty. Replace them as needed to ensure normal airflow into the system.

Explore Our Case Studies Call To Schedule An Appointment

The Outdoor Temperature

All HVAC systems have a rated capacity for cooling and heating. Contractors help clients find a unit of the right size for their homes using the relevant factors. However, the weather may exceed the expected temperature range in the region at times. A heat pump may have a tough time during frigid weather. It may not be able to provide adequate heating, so a supplementary heating system is needed to support it. Unfortunately, the supplementary heat needs more power, which may trip the breakers. Consider wearing more warm clothes and turning the heat down instead to prevent it from happening again.

Frozen Outdoor Heat Pump Coils

ice on coil cooler of dirty heat pump

The outdoor unit of the heat pump has a coil that needs constant airflow for effective operations. If these coils freeze, the ice will prevent the air from flowing through. The system will not work as efficiently. It will work harder to achieve the temperature settings, which can even backfire as the system overworking can result in system shutdown. You may be tempted to chip the ice off using a sharp object, but this can only cause damage to the system. It is best to turn off your heat pump to let the ice melt naturally before using it again.

Heat Pump Water Leaks

Survey the outdoor unit’s immediate surroundings and search for anything that can cause frozen coils. Prevent this issue from recurring by finding the source of excess moisture. It can be due to gutter run-off. Cold water may be dripping to the ground from the roof directly overhead. Use a roofer to resolve this issue. Ensure that the outdoor unit has a two-foot clearance around its perimeter for good air movement.

Call To Make An Appointment

Poor Air Circulation

The outdoors has many elements that cannot be controlled. Therefore, homeowners need to conduct regular checks on the unit, so any unusual situations are dealt with right away. For instance, fallen leaves may have gotten inside the unit and are blocking air circulation. Remove any debris on or around the unit immediately. Move any objects nearby as well. If plants are growing nearby, ensure that you trim them regularly. You can build a canopy to protect the unit from any falling debris, just make sure there is enough clearance.

Heat Pump Has Low Refrigerant

A leak in your heat pump can cause refrigerants to flow out. As a result, there will be insufficient refrigerant to ensure the system does its job. The performance of the heat pump will slowly drop until it completely shuts down. Call an HVAC technician to find and repair the leak before this happens. They will also top up the refrigerant in the system.



Heat pumps influence the environment they are installed in. However, the environment can also affect it. Some of the elements around it can change how heat pumps work. Therefore, homeowners need to check on vulnerable parts and intervene when needed. The troubleshooting steps in this article can help in many situations. Call a licensed HVAC technician if the problem persists. HVAC professionals can give an accurate diagnosis and a long-lasting solution.

Learn More About Our Heat Pump Repairs Call To Schedule A Free Estimate

Call Lawes Company For All Of Your HVAC Requirements

Lawes Company Logo

Lawes Company provides high-quality HVAC services in Monmouth and Ocean Counties, New Jersey. We have the best highly trained and professionally certified technicians on staff. They can conduct top-notch heating and cooling repairs, installations, maintenance, and replacements. Rest assured, all of our technicians are equipped with the right tools, knowledge, and experience to service your HVAC system correctly.

Our company offers the most competitive heating and cooling service prices in the area. Our tune-up services can enhance your comfort and increase energy efficiency while reducing your energy costs. If you need an HVAC repair or replacement system, we can recommend the most suitable solution within your budget. Your satisfaction is our priority, so all of our work is guaranteed. Give Lawes Company a call today to schedule a service appointment. We offer free, in-home estimates.

Call Now: (732) 741-6300 Read Our Reviews

Contact us now at (732) 741-6300 to find out more!