An air-source heat pump typically lasts 12 to 15 years, and a well-installed, well-maintained one can pass 20. Ductless mini splits have a similar lifespan. Geothermal systems last longer: 20 to 25 years for the indoor unit and 50 years or more for the underground loop.
Why heat pumps last a bit less than AC units
A heat pump runs in both summer and winter, so it clocks up more hours a year than an air conditioner that only runs in summer. The outdoor unit also goes through defrost cycles in winter, which add wear. Modern inverter heat pumps help, because they ramp up and down smoothly instead of starting and stopping at full power.
What shortens a heat pump’s life
- Oversizing: a unit that is too big short-cycles, starting and stopping many times an hour. Starts are the hardest moment for a compressor.
- Poor installation: wrong refrigerant charge, a poor vacuum, or moisture left in the lines can cut years off the compressor.
- Dirty filters and coils: they force the system to run hotter and longer.
- Coastal salt air: corrodes coils. Coated coils or regular rinsing help.
- Skipping maintenance: small problems like a weak capacitor can take out a fan motor or compressor.
How to make a heat pump last longer
- Replace or clean the filter every 1–3 months.
- Keep the outdoor unit clear of leaves, snow and plants.
- Book a professional tune-up once a year. See the heat pump maintenance checklist.
- Avoid big thermostat setbacks that force long runs on backup heat.
- Fix leaks when found rather than repeatedly topping up refrigerant.
Signs your heat pump is near the end
- It is more than 12–15 years old and needs a major repair
- It uses R-22 refrigerant (phased out; recharges are very costly)
- Energy bills rise year after year without a change in use
- Rooms stay uncomfortable even after service
- Repeated repairs in the last two years
Repair or replace?
Multiply the unit’s age by the repair cost. If the result is above about 5,000, replacement usually makes more sense. A compressor replacement on a 12-year-old system (12 × $2,000 = 24,000) is a clear case for replacement. A $200 capacitor on a 6-year-old unit is not.
When you do replace, a new system will almost certainly be more efficient than the old one. See heat pump installation cost and estimate your savings with the SEER2 savings calculator.