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Common Heat Pump Problems and How to Fix Them
Snowed-in days should be about spending quality time with family, relaxing with a warm beverage, or investing in a hobby. None of these cold season pleasures should involve worrying about a failing heat pump during the unpredictable Indiana storms. That’s why we’ve compiled a guide on common heat pump issues with tips on how to fix them to keep you comfortable for the rest of the winter.
The heat pump is not running
If your unit fails to start, then these are the likely culprits:
Thermostat issues: If you have a programmable thermostat, is it set to have the heat come on at the right time? If this time is correct, then your thermostat might not be calibrated correctly, which means it will read the wrong temperature. Additionally, is your thermostat compatible with your heat pump? A heat pump requires an additional wire from a regular AC thermostat because of its ability to control heating and cooling.
If none of these are the issue, then improper wiring could be preventing the thermostat from connecting to the heat pump. A thermostat that hasn’t been wired correctly can fry electrical circuits, thus making the heat pump malfunction. An HVAC technician will be able to determine whether or not your thermostat is sending the proper signals to your unit, and this is the kind of issue that can be flagged during system tune-ups as well.
Power failures: If your heat pump trips your circuit breaker, then that means the heat pump is trying to pump too much power from the circuit. Check the main electrical panel and any subpanels that help power the unit. Simply flipping the switches on and off again can resolve the issue.
If you reset the breaker once and it does not trip again, then you are likely fine. However, if the breaker trips again, you should leave the power off to your heat pump and call a professional immediately. The circuit breaker cutting the power during overuse can prevent an emergency like an electrical fire. If the breakers aren’t the problem, then you might have a blown fuse.
A broken starter capacitor: The starter capacitor transmits the electrical charge that turns on the heat pump’s motors. To diagnose this issue, listen to your unit. A telltale sign of a failed capacitor is a faint clicking noise that happens at the same time the heat pump should be turning on. Replacement requires a technician.
A faulty reversing valve: A reversing valve allows the heat pump to heat as well as cool by reversing the direction of the refrigerant, which is a substance used for heating and cooling the home. A faulty valve means that your system could be stuck in cooling mode. Check and see if your unit turns on when you request cool air, but fails when you opt for heat. If this is the case, then you’ll need a technician to replace the valve.
The heat pump is frozen
A thin layer of ice and snow on the outside unit of your heat pump should not stop it from blazing ahead, but if the whole unit is frozen up, you’ll have issues. A frozen heat pump should not be ignored, as it can lead to permanent damage in the system’s fins and blades. The freezing can also lead the compressor, the part that moves the refrigerant through the system, to fail, which means you will have to invest in a new unit.
Once it detects a certain temperature, the heat pump enters defrost mode to melt the ice and minimize system damage. This built-in defrost mode should be sufficient for melting frost and light snow. If the defrost mode is failing to turn on in mild winter conditions, then the source could be an issue with the system’s controls or sensors. The reversing valve might also be failing to switch the system. Lastly, the defrost relay might be malfunctioning. This component is essential because it’s used for turning on the compressor, switching the reversing valve, and stopping the fan blades.
The good news is that it’s not too hard to mitigate unit damage. If defrost mode is not working, then you can use a delicate process to avoid severe damage to your unit. First, turn off the heat pump at the circuit breaker. Rather than trying to chip off the ice, use a hose to gently pour warm water over the ice and gradually melt it away. If there is enough heat at this point, you might be able to successfully reactivate the heat pump to melt the rest of the ice away.
It should also be noted that during defrost mode the system can temporarily output cold air. Some homeowners install supplemental heating options like electric-resistance heat strips to keep their home warm during cold winter nights when the heat pump is on its short defrost cycle.
Here are some additional issues that can lead to your unit freezing up:
The outdoor fan is lagging: If the fan motor quits while the heat pump is in heating mode, then the unit’s outdoor coils will quickly freeze and the defrost cycle will likely fail. To discover a fan issue, turn off the unit power and check for debris to see if anything like a stick, bird’s nest, or even animal could be preventing the blades from spinning. If the fan won’t start spinning with a little nudge, then the motor or capacitator (the part that runs the fan and motor) has failed. Trying to run a heat pump without the fan will cause severe damage to the compressor, so don’t even try to. This is a situation in which to immediately call your technician to evaluate for repairs.
Low refrigerant levels: Without sufficient refrigerant, your heat pump will struggle to bring enough heat indoors. Have a professional come out to check if the levels are too low or if your system needs to be recharged. If your heat pump system has a slow leak of refrigerant, eventually the charge becomes so low that the system will not be able to generate enough heat to melt the frost, let alone heat your home.
Leaking gutters: Consistent dripping from leaky gutters can lead to a layer of ice forming on top of the unit. To avoid, or at least minimize, the amount of moisture that could freeze, check for cracks and holes in your gutters. Look out for drainage as well so that the system isn’t in danger of absorbing and storing water.
Indoor air vents are blocked: Indoor air vents might be obstructed by furniture, clothing, or other items. Clear away any obstacles to support warm air flowing freely into your home.
The heat pump is running constantly
Heat pumps are designed to work much more gradually than a furnace, so longer cycles are expected. If temperatures are extremely cold, then you can expect your heat pump to be running continuously without it being an issue. If you’re finding your heat pump cycling frequently in mild temperatures, however, then these are some common issues:
Clogged air filter: Naturally accumulated dirt in the system make the heat pump work harder to distribute the same amount of warm air. As a result, your unit will be running for a much longer period of time. This issue can easily be avoided by changing the air filter at least once a month.
Improper unit sizing: Undersized units will wear down faster, running longer and using more power to meet the demands. On the other end of the spectrum, an oversized unit will consume excess electricity. Before installing your heat pump, a technician should have performed a load calculation, which would have determined the correct size heat pump you need for your home. Unfortunately, if your heat pump system is not the right fit for your home’s heating needs, the best solution is to replace it with a system that is the correct size (or else waste energy or wear down your system quickly).
The refrigerant is leaking: Depleted refrigerated levels are putting strain on the system to transfer heat into the home. Therefore, the heat pump has to run longer, and use more power, to reach the set temperature.
Get comfortable again
While homeowners benefit from the energy efficiency of heat pumps to complement their furnaces, without proper maintenance, that energy savings gets eaten up in repairs. Although some of these fixes, such as checking your vents, can be done at home, we encourage you to reach out to professionals for the more severe issues for your safety and your system’s longevity. Now you can plough one more winter hassle out of the way and get back to relaxing in warmth.