Heat pumps are low-maintenance, but not no-maintenance. Skip the simple stuff and you'll lose 15–25% efficiency within a few years, void your manufacturer warranty, and shorten the unit's life by 3–5 years. Stay on top of it and a heat pump runs reliably for 12–15+ years. Here's the checklist.
DIY tasks (every 1–2 months)
Three things any homeowner can and should do regularly:
1. Clean the indoor filters
Open the indoor unit cover (it lifts up — no tools), pull the filters out, vacuum off loose dust, rinse under cool water if visibly dirty, dry completely, and put them back. 5 minutes. Do this every 1–2 months — more often in dusty environments or pet-heavy homes. Dirty filters are the single biggest preventable cause of efficiency loss.
2. Keep the outdoor unit clear
Make sure leaves, garden debris, spider webs, and rubbish don't accumulate around the outdoor condenser. The unit needs free airflow on all sides to work efficiently. Hose it down gently from a few feet away if it's looking grimy — but don't blast water directly into the electronics.
3. Check the condensate drain
Find where the condensate water drains outside. During cooling mode in summer, you should see a steady drip. If it's bone dry, the line might be blocked — water will eventually back up into the indoor unit and leak from the casing onto your wall or ceiling. Catch this early.
Seasonal checklist
Spring (Sep–Nov)
- Clean indoor filters
- Switch from heating to cooling mode and run a full test cycle
- Check the outdoor unit for debris (leaves, branches, dust)
- Schedule annual professional service if not done in autumn
Summer (Dec–Feb)
- Clean indoor filters every 4–6 weeks during heavy use
- Check that condensate drainage is flowing freely outside
- Listen for unusual noises during heavy cooling load
- Use dehumidify mode on muggy days to reduce indoor moisture
Autumn (Mar–May)
- Clean indoor filters
- Switch from cooling to heating mode and run a full test cycle
- Schedule annual professional service before winter starts
- Clear outdoor unit of fallen leaves and autumn debris
Winter (Jun–Aug)
- Clean indoor filters every 4–6 weeks during heavy use
- Check the outdoor unit isn't iced over (light frost is fine; heavy ice means call for service)
- Watch for reduced output — could indicate refrigerant or sensor issue
- Don't put a cover over the outdoor unit while it's running
Annual professional service (essential)
Once a year is the manufacturer recommendation across every brand — Mitsubishi Electric, Daikin, Hitachi, Fujitsu, Panasonic. Heavy-use units (commercial premises, rentals, primary heating) benefit from twice-yearly servicing. A standard annual service should include:
- Indoor unit deep clean — filters, fan, evaporator coil, drain tray
- Outdoor unit clean — condenser coil, fan, mounting check
- Refrigerant pressure check and top-up if required
- Electrical connections inspection
- Sensor calibration and operational test (heating + cooling + defrost)
- Drain line flush
- Written report you can keep for warranty records
Costs $150–$220 for a single high-wall unit, $250–$400 for multi-zone or ducted systems. Pays for itself in efficiency gains alone.
Warning signs that mean call now (not next month)
- Water leaking from the indoor unit
- Burning or musty smells when the unit runs
- Outdoor unit heavily iced over and not clearing on its own
- Grinding, gurgling, or rattling noises
- Error codes on the controller
- Heating or cooling output noticeably reduced
- Tripped circuit breaker that won't stay reset
Frequently asked questions
How often should I clean my heat pump filters?
Every 1–2 months of regular use, more often in dusty environments or homes with pets. Pull the filters out, vacuum the loose dust, rinse under cool water if needed, dry completely, and put them back. A 5-minute job that meaningfully extends the life of the unit.
Can I clean a heat pump myself?
The indoor filters yes — that's homeowner-level maintenance and we'd encourage you to do it regularly. The internal coils, drain tray, refrigerant system, and electrical connections need a licensed technician. Don't open the indoor unit casing or touch the outdoor refrigerant pipework.
What does an annual heat pump service include?
Indoor unit deep clean (filters, fan, evaporator coil, drain tray), outdoor unit clean (condenser coil, fan, mounting check), refrigerant pressure check and top-up if needed, electrical connections inspection, sensor calibration, drain line flush, and full operational test on heating, cooling, and defrost cycles.
What happens if I never service my heat pump?
Three things, in order: first, efficiency drops 15–25% within a few years (showing up on your power bill). Second, manufacturer warranty becomes void since most warranties require professional servicing. Third, the unit fails earlier — typically 8–10 years instead of 12–15 — and the failure mode is usually expensive (compressor or PCB).
When should I call a technician for my heat pump?
Annual service (mandatory), plus any time you notice: water leaking from the indoor unit, unusual noises (grinding, gurgling, rattling), reduced heating or cooling output, ice forming on the outdoor coils that doesn't clear, error codes on the controller, or burning/musty smells when the unit runs.
Is heat pump maintenance worth the cost?
Yes — a $180 annual service typically saves $200+ in efficiency gains over the year, plus catches small issues before they become $1,500 emergency repairs, plus extends the unit's working life by years. Annual servicing has the highest ROI of anything you can do for the unit.
