What You Need to Do Every Month
The single most important maintenance task is checking and replacing your air filter every month during heating and cooling season. A clogged filter forces your heat pump to work harder, wastes energy, and can damage the compressor over time. Look at your filter—if you can't see light through it, replace it. Most residential filters cost $15 to $30 and take two minutes to swap out.
While you have the filter out, visually inspect the indoor unit for dust buildup around the vents and coils. Use a soft brush or vacuum with a brush attachment to gently remove surface dust. Do not use water or compressed air on the coils themselves; that can bend the fins and reduce efficiency. If you see ice forming on the outdoor unit during winter, that is normal during defrost cycles, but thick ice buildup means something is wrong and you should call a technician.
Key Takeaways
- Replace your air filter monthly during heating and cooling seasons, or whenever it looks clogged, to prevent your heat pump from overworking.
- Clear leaves, grass, and debris from around the outdoor unit at least twice a year so air can flow freely through the condenser coils.
- Have a licensed technician inspect your system once per year, ideally in the fall before heating season, to check refrigerant levels and electrical connections.
- Keep the area around both indoor and outdoor units clear of obstructions, and trim tree branches at least three feet away from the outdoor unit.
- If your heat pump stops heating or cooling, or makes unusual noises, contact a technician rather than trying to repair it yourself.
Cleaning the Outdoor Unit
The outdoor condenser unit needs clear airflow to work properly. At least twice a year—once before heating season and once before cooling season—walk around the unit and remove leaves, grass clippings, dirt, and any other debris. Use your hands or a soft brush; do not use a pressure washer, which can damage the aluminum fins.
Check that nothing is blocking the sides or top of the unit. Keep shrubs, fences, and air conditioning units at least two feet away. Trim tree branches so they hang at least three feet above the outdoor unit. In winter, gently brush away snow and ice that accumulates on the unit, but do not chip at it with tools—let the defrost cycle handle most of it naturally.
If you live near the ocean or in a salty environment, rinse the outdoor coils with fresh water once a year to prevent corrosion. Use a garden hose on low pressure, spraying from top to bottom. Never spray directly into the unit's electrical components or fan motor.
Annual Professional Inspection
Schedule a service visit once per year, ideally in the fall before you rely on heating. A licensed technician will check refrigerant levels, test electrical connections, inspect the compressor, and measure airflow. They will also clean the indoor and outdoor coils more thoroughly than you can do yourself. This typically costs $150 to $300 and can catch small problems before they become expensive repairs.
During the visit, ask the technician to show you the filter location and the correct filter size so you can replace it confidently between visits. If they find that refrigerant is low, that means there is a leak somewhere—do not let them straightforward top it off without finding and fixing the leak, or you will be back in a few months with the same problem.
What to Check Before Winter and Summer
Two weeks before you expect to need heating or cooling, do a quick system check. Set your thermostat to the mode you are about to use—heat in fall, cool in spring—and let it run for 15 minutes. The air coming from your vents should feel noticeably warm or cool. If it does not, or if the system cycles on and off constantly, call a technician before the season gets busy and appointments fill up.
Check that your thermostat batteries are fresh if it uses them. A dead battery will not prevent heating or cooling, but it may prevent your system from responding to your commands. Replace batteries annually, in the fall, as part of your seasonal prep.
Signs You Need to Call a Technician
Do not wait for your annual visit if you notice any of these problems. Unusual noises—grinding, squealing, or rattling—usually mean a mechanical part is wearing out. Frost or ice on the indoor unit during winter, or the system blowing cold air when set to heat, suggests a refrigerant leak or valve problem. If one room stays much colder or warmer than others, the system may have a ductwork issue or an airflow blockage.
A sudden spike in your energy bill, with no change in your usage, often means the heat pump is working harder because something is wrong. Weak airflow from your vents, even after you have replaced the filter, can indicate a duct leak or a failing blower motor. Any of these warrant a service call from a licensed technician—attempting repairs yourself can void your warranty and create safety hazards.
Keeping Your Thermostat and Controls Working
Your thermostat is the brain of your heat pump system. Keep it away from direct sunlight, heat sources, and cold drafts, because it reads the temperature around it to decide when to turn the system on and off. If it is in the wrong spot, your system will run too much or too little.
Programmable and smart thermostats let you set different temperatures for different times of day, which saves energy when you are away or asleep. If your thermostat has a display, check it occasionally to make sure it is reading a reasonable temperature for your home. If the display is blank or unresponsive, replace the batteries first; if that does not work, you may need a new thermostat.
Seasonal Storage and Shutdown
Heat pumps run year-round in most climates, so there is no shutdown season. However, if you live somewhere with very mild winters and do not use heating, you can switch your system to cooling-only mode in winter to avoid unnecessary operation. Do the same in summer if you do not use air conditioning—set it to heating-only mode. This reduces wear on parts you are not using.
If you are leaving your home empty for more than a few weeks, set your thermostat to a moderate temperature—around 62°F in winter, 78°F in summer—to prevent pipes from freezing or the house from becoming dangerously hot. Do not turn the system off completely, because that can allow humidity to damage indoor components.
Frequently Asked Questions
How often should I replace my heat pump air filter?
Check your filter monthly during heating and cooling seasons. Replace it whenever it looks clogged or dirty—usually every one to three months, depending on dust levels in your home, whether you have pets, and the filter's MERV rating. Higher-MERV filters trap more particles but clog faster.
Can I clean the outdoor unit myself, or do I need a technician?
You can remove leaves and debris with your hands or a soft brush. For a thorough coil cleaning with special equipment, hire a technician. They have tools to clean without damaging the fins and can spot problems you might miss.
What does it mean if my heat pump is making a hissing sound?
Hissing usually indicates a refrigerant leak. This is not something to ignore—call a technician to locate and repair the leak. Running the system with low refrigerant damages the compressor and will cost much more to fix later.
Is it normal for my heat pump to frost up in winter?
Light frost on the outdoor unit during winter is normal and part of the defrost cycle. The system will melt it automatically. Heavy ice buildup that does not melt, or frost on the indoor unit, means the defrost cycle is not working properly and you should have it checked.
How much does annual heat pump maintenance cost?
A professional annual inspection typically runs $150 to $300. Some companies offer maintenance plans that bundle the annual visit with priority service and discounts on repairs, which may save money if you need service during the year.