Heat Pumps: Pros, Cons and Common Failures

Heat pumps have become a popular choice for heating and cooling, including in colder parts of the country where they were once uncommon. They can be efficient and versatile, but they work differently than a furnace and air conditioner, and they have their own repair needs. Here is what to know.

How a heat pump works

A heat pump moves heat rather than creating it. In summer, it works like an air conditioner, pulling heat from inside your home and releasing it outdoors. In winter, it reverses the process, pulling heat from the outdoor air (or the ground, for geothermal systems) and bringing it inside.

A component called the reversing valve switches the direction of refrigerant flow between heating and cooling modes. Many systems also include backup electric heat strips or pair with a gas furnace for very cold weather.

Common types include:

• Air-source heat pumps with an outdoor unit and indoor air handler
• Ductless mini-splits with indoor wall or ceiling units and no ductwork
• Geothermal (ground-source) systems that use buried loops

Pros of heat pumps

• One system handles both heating and cooling
• Often more efficient than electric resistance heating
• No combustion inside the home on all-electric systems
• Ductless options work well for additions or homes without ducts
• Newer cold-climate models are designed to work in lower temperatures

Cons of heat pumps

• Heating output can drop in very cold weather, which may require backup heat
• Backup electric heat can raise electric bills when it runs often
• The outdoor unit runs year-round, so it sees more wear than a cooling-only AC unit
• Installation can cost more up front than replacing a single furnace or AC unit
• Repairs often need a technician familiar with heat pump controls

Common heat pump failures

Heat pumps share many parts with central air conditioners, plus a few of their own. Common problems include:

1. Reversing valve failure. The system may get stuck in heating or cooling mode.
2. Defrost problems. In winter, the outdoor coil can frost over. A defrost control and sensor manage this. If they fail, ice can build up and cut efficiency.
3. Capacitor and contactor failures. These inexpensive electrical parts often cause the system to stop starting.
4. Compressor failure. One of the most expensive repairs, sometimes leading owners to consider replacing the outdoor unit.
5. Refrigerant leaks. A slow leak reduces performance and can strain the compressor.
6. Fan motor failure in the outdoor unit or indoor air handler.
7. Thermostat or control issues, especially with systems that use backup heat.

Signs your heat pump needs service

• Warm air in cooling mode or cool air in heating mode
• Ice that stays on the outdoor unit for a long time
• Backup heat running much more than usual
• Short cycling, where the system turns on and off quickly
• New noises like grinding, buzzing, or loud clicking
• Higher energy bills without a change in use

Some steam or a whooshing sound from the outdoor unit in winter is normal during a defrost cycle. A unit that stays caked in ice for hours is not. If you're unsure, a technician can check the defrost controls and refrigerant charge.

Maintenance tips

• Change or clean filters regularly
• Keep the outdoor unit clear of snow, leaves, and debris
• Schedule professional maintenance as recommended by the manufacturer
• Keep supply and return vents open and unblocked
• Keep records of service, since warranties often require proper maintenance

Heat pumps and home warranties

Many home warranty plans cover heat pumps as part of their heating and cooling coverage, but terms vary. Check whether the plan covers the reversing valve, defrost controls, and refrigerant recharges. Some plans cap refrigerant or replacement costs, and some exclude ductless or geothermal systems or charge extra for them. Our pages on heating coverage and air conditioning coverage explain what's commonly included. If your system uses ducts, ductwork coverage may matter too.

How Warranty Wizards can help

We help you compare home warranty plans from independent third-party providers and check how each one covers heat pumps. We'll explain what a plan covers before you buy. Get a free quote at /get-a-quote/.