Heat Pump Not Working: Here's What You Need to Know

          

Heat pumps are highly efficient HVAC systems that provide year-round comfort by heating and cooling your home. However, when something goes wrong, it often traces back to one or more heat pump components failing to operate correctly. But when it stops working, it can leave you without essential climate control when needed. The good news is that many of these problems are common and manageable. In this article, we’ll explain how a heat pump works, highlight typical malfunctions and fixes, share preventative tips, and guide you on when to seek professional help.

Common Causes and Fixes for Heat Pump Not Working

Here are some common issues and solutions to consider when your heat pump isn't working properly.

Incorrect Thermostat Settings or Malfunctions

The thermostat serves as the control center for your heat pump system, dictating the operation of the heating and cooling modes based on the temperature set by the user. If it’s malfunctioning or incorrectly set, it can lead to system inefficiencies or complete system failure.

Fix:

• Ensure that the thermostat is set to the appropriate mode—either heating or cooling—based on the season.

• If the thermostat runs on batteries, make sure it's getting enough power by changing the batteries.

• You can also reset the thermostat to its factory settings if the settings were mistakenly altered.

• Future faults may be decreased by switching to a smart thermostat with more precise temperature control and diagnostic capabilities.

• If problems persist, it’s advisable to call an HVAC technician to inspect the thermostat's wiring or sensor calibration for any issues, as this may affect other heat pump components.

Tripped Circuit Breaker or Power Supply Issues

If your heat pump isn’t receiving power, it simply won’t function. Electrical interruptions, such as a tripped circuit breaker or internal faults, are common causes of power loss. These issues can occur without warning, particularly if the system has been subjected to a power surge or electrical fault.

Fix:

• Check your electrical panel for any tripped circuit breakers and reset them as needed.

• Inspect the disconnect switch near the outdoor unit to make sure it’s turned on.

• If the breaker trips again after resetting, it may indicate a more serious issue, such as a short circuit or a malfunctioning capacitor. In this case, it’s essential to call a professional HVAC technician for further diagnosis and repairs.

Dirty or Clogged Air Filter

One of the most common causes of heat pump malfunction is a dirty air filter. When the air filter becomes clogged with dirt, dust, and debris, it restricts airflow, forcing the system to work harder. This leads to inefficiency, and in some cases, the system may shut down completely due to overheating.

Fix:

• Replace or clean the air filter every 1 to 3 months to ensure proper airflow.

• Use filters with an appropriate MERV rating (typically between 8 and 13 for residential systems).

• Consider setting calendar reminders or using a smart thermostat that can notify you when it’s time to replace the filter, preventing performance issues from occurring in the first place. Regular filter replacement helps maintain the health of your heat pump components, such as the evaporator coil and blower motor.

Frozen Outdoor Unit or Coils

While it’s normal for the outdoor unit of your heat pump to develop a light frost in colder weather, excessive ice buildup can hinder the unit’s ability to extract heat. When ice builds up around the outdoor coil, the heat pump’s efficiency decreases, and it may not be able to properly heat your home.

Fix:

• Power down the system and allow the ice to melt naturally.

• Remove any debris, leaves, or snow that may be obstructing airflow around the outdoor unit.

• Ensure that the outdoor unit is positioned above any pooling water or excessive snow, as standing water can contribute to ice buildup.

• If the issue persists, there may be a malfunction in the defrost cycle or a faulty sensor, which would require the attention of a professional HVAC technician. Failure in these heat pump components can significantly reduce the system’s performance.

Low Refrigerant Levels or Leaks

Refrigerant is an essential component in the heat pump’s operation, allowing it to transfer heat between the indoor and outdoor coils. If the system is low on refrigerant due to a leak, it can no longer efficiently heat or cool your home. This may lead to system breakdowns and reduced performance.

Fix:

• Refrigerant issues should only be handled by a licensed HVAC technician, as dealing with refrigerant requires specialized knowledge and tools.

• The technician will locate and repair any leaks and then recharge the system with the proper refrigerant amount, restoring its ability to transfer heat efficiently.

• Regular maintenance checks can help detect refrigerant leaks early, allowing for prompt repairs before significant performance issues arise.

Malfunctioning Reversing Valve

One essential part of a heat pump system is the reversing valve. It permits the heat pump to alternate between modes of heating and cooling. The heat pump may not be able to switch between modes, making it useless for either heating or cooling, if this valve gets stuck or malfunctions.

Fix:

• If the reversing valve malfunctions, it will require a trained technician to assess its functionality.

• The technician will test the valve to determine whether it’s stuck or defective. To enable the system to switch between heating and cooling modes again, the valve may need to be changed.

• Replacing the reversing valve is a complex task that should be handled by professionals, as improper repairs can further damage the system.

Capacitor or Compressor Failure

Capacitors and compressors are vital components of the heat pump’s operation. The capacitor supplies the electrical charge needed to start the compressor and fan motors, while the compressor is responsible for circulating refrigerant throughout the system. If either of these components fails, the heat pump will not function.

Fix:

• A faulty capacitor can usually be replaced by a technician, as it’s a relatively simple fix.

• If the compressor fails, the repair may be more complex and expensive. In some cases, it may be more cost-effective to replace the entire unit, especially if the system is older.

• Regular maintenance helps identify early signs of wear in these components, allowing for replacement before failure occurs.

Short Cycling 

Short cycling occurs when a heat pump turns on and off too frequently without completing its full heating or cooling cycles. This reduces the system’s efficiency and places additional strain on its components, potentially shortening the system’s lifespan.

Fix:

• Ensure that the thermostat is placed in a location where it can accurately measure room temperature, away from heat sources or direct sunlight, which can cause false readings.

• Replace dirty air filters to ensure unrestricted airflow, as clogged filters are a common cause of short cycling.

• Ensure that the heat pump is properly sized for the space it is conditioning. If the system is too large or too small, it may result in short cycling and inefficient operation.

• In some cases, a professional HVAC evaluation may be needed to identify and correct refrigerant or electrical issues causing the short cycling.

Improper Installation or Incorrect Sizing

A heat pump that was installed incorrectly or is improperly sized for the space it serves will struggle to provide consistent comfort. Incorrect installation can lead to issues like improper refrigerant charging, inefficient airflow, and overheating. If the heat pump is too small or too large for the home, it may not be able to meet the heating and cooling needs effectively, leading to frequent breakdowns or inefficiencies.

Fix:

• Have an HVAC professional perform a manual load calculation to determine whether the heat pump is appropriately sized for your space.

• If improper installation or ductwork issues are the cause, these should be corrected immediately by a licensed professional.

• In some cases, replacing the unit may be necessary to achieve optimal performance and energy efficiency.

Lack of Regular Maintenance

Routine maintenance is key to ensuring that your heat pump operates efficiently and lasts for many years. Without regular maintenance, components can wear out, and issues can go unnoticed until they cause system failure.

Fix:

• Schedule an annual maintenance checkup with an HVAC technician to clean components, check refrigerant levels, inspect the reversing valve, and identify any early warning signs of trouble.

• Clean and replace air filters as needed, and check the outdoor unit for debris buildup.

• Ensure that the unit is operating at peak efficiency with proper lubrication of moving parts and calibration of sensors and controls.

Old or Worn-Out System

Over time, all HVAC systems, including heat pumps, will experience wear and tear. As your heat pump ages, its components may become less efficient, resulting in decreased performance and, eventually, system failure. A heat pump that is past its prime may require more frequent repairs, higher energy bills, and a greater risk of breaking down during extreme weather conditions.

Fix:

• If your heat pump is over 10-15 years old and frequently breaks down, it may be time to consider replacing it. Modern heat pumps are more energy-efficient, providing better comfort at a lower long-term cost. A replacement can improve performance and reduce future breakdowns.

• If your heat pump is relatively young but suffering from wear, have an HVAC technician evaluate the system. If the cost of repairs approaches the cost of replacement, upgrading to a newer, more efficient model might be the most cost-effective option.

Understanding the common causes behind heat pump issues and their fixes can save homeowners time, money, and frustration. Regular maintenance and early detection of problems are essential to extending the lifespan and performance of your heat pump. If you're unsure about handling any of these repairs, it’s always best to consult with a professional HVAC technician to ensure the system remains in top condition for years to come.

Written by Allen Rode for PartsHnC, your trusted source for high-quality HVAC parts, including water heater components, air conditioner parts, and heat pump solutions.