Why Can’t You Get Your Heat Pump to Turn On?

Heat Pump in Charlotte, NC

In places like Charlotte, where the winter weather is usually mild, a heat pump is typically the most practical and effective option for heating and cooling your home. Since heat pumps are used throughout the entire year, they should undergo preventative maintenance every spring and fall. Without professional care, heat pumps can break down more frequently and experience various issues that limit their effectiveness. There are also a few different problems that can prevent the heat pump from starting, and here is a quick overview of what can cause this to happen and how to overcome it.

Malfunctioning or Improperly Set Thermostat

The first thing to do if you find that your heat pump won’t start is to check the settings on your thermostat. Verify that the thermostat is set to the proper mode (heating or cooling) and that you have the temperature set correctly. If you have the thermostat programmed with varying temperature settings for different times or days of the week, you will also want to check that these settings are correct.

If you have any issues checking or adjusting the programmed settings, you can turn the thermostat to its manual mode. When you do this, you can adjust the thermostat either higher or lower than the temperature it shows, depending on whether you are trying to direct your system to cool or heat your home.

If the thermostat shows a low battery, you’ll need to shut it off, replace the batteries, and try to turn it on again. The batteries in a thermostat don’t just power its display. They also work to allow your thermostat to send a signal for the indoor blower fan and heat pump to turn on whenever the temperature inside needs to be raised or lowered. If the thermostat shows a low battery, the current batteries do not have sufficient charge to send this signal.

If the thermostat is set correctly and the batteries don’t need to be replaced, there might be a problem in the thermostat wiring preventing the signal from reaching the heat pump. Another possibility is that the thermostat is not calibrated correctly. If the thermostat isn’t properly calibrated, the temperature it displays may not be accurate, and this can also prevent it from signaling the heat pump to run.

Electricity Supply Issues

After checking the thermostat, the next step is to ensure that the heat pump has power. Most systems will have a power shut-off located outside the home on the wall near the heat pump. If so, check that the switch is in the “on” position. Next, go back inside to your main electrical panel and ensure that the circuit breaker for the heat pump isn’t tripped.

Heat pumps can potentially experience a number of issues that will cause them to overload the circuit and trip the breaker when the unit tries to start. If the breaker is tripped, turn it back on and see if your heat pump will now run. If the breaker instantly trips again when the heat pump tries to start, you will need to have the unit inspected by a certified HVAC technician to identify the source of the problem and have it repaired.

This issue most commonly occurs because the compressor motor in the heat pump has failed. It could also happen due to an electrical short within the heat pump or in the wiring running to the unit. This issue will cause a short circuit and overload the breaker whenever the heat pump attempts to run.

If the problem is related to the compressor motor, you will likely need to replace your heat pump. It is possible to replace this motor, but this usually costs about the same as buying a new unit. As a result, replacing the motor is usually only done if the unit is fairly new and still covered by the original manufacturer’s warranty.

Failed Start Capacitor

A failed start capacitor will also prevent your heat pump from turning on. Heat pumps and most other types of HVAC units require a large amount of energy for their motors to start, and the capacitor helps to supply and distribute this energy. It works by storing a strong charge that it releases to power up the compressor motor and fan motor in the heat pump. If the capacitor fails, there won’t be sufficient electricity to initiate this, and the heat pump will not start.

A failed capacitor is usually an easy problem to diagnose. Checking whether the capacitor is working is a two-person job. One person needs to be inside to adjust the thermostat to the temperature that the heat pump should start. The other person must stand outside next to the heat pump to listen to it. If the capacitor has failed, you will hear a clicking noise from inside the heat pump when it attempts to start. If you hear this noise, you will need to have a technician replace the capacitor.

Faulty Reversing Valve

The reversing valve enables heat pumps to switch between heating and cooling. It works by changing the direction of the refrigerant home, depending on what mode the heat pump is on. If the reversing valve fails, the direction of the refrigerant flow will not change, and the heat pump will get stuck in either cool or heat mode. This problem is often not immediately noticeable, and you will only realize it when it is time to switch from cool to heat or heat to cool.

A faulty reversing valve is another issue that is simple to diagnose. All you need to do is switch between modes and adjust the thermostat. If the heat pump starts up in one mode but not the other, it is an obvious indicator that the reversing valve is faulty and must be replaced.

Air Handler Issues

Multiple issues can occur with your indoor air handler and blower fan that can prevent your heat pump from controlling the temperature in your home. In many cases, these problems will make it seem like your heat pump is not working when the actual issue is that the blower fan is not circulating air. If the blower does not start, the heat pump will usually shut down soon after starting to avoid overheating.

In some situations, the blower motor has failed and needs a replacement. In other cases, the start capacitor on the blower has failed. Electrical supply and wiring issues can also prevent the blower from turning on. All these problems will result in no air coming out of your vents, which is an obvious sign that you must have your blower fan inspected and repaired.

If you need your heat pump repaired or maintained, Integrity Heating & Cooling has you covered. We service all heat pump models and offer expert heat pump installation services. In addition, we work on and install air conditioners, furnaces, mini-splits, and indoor air quality units. We also offer duct cleaning, duct sealing, and a full range of commercial HVAC services for customers throughout the Charlotte area. We have residential and commercial financing plans for your convenience. If you have any heat pump issues or need any other heating or cooling service, give Integrity Heating & Cooling a call today!