How to make a heat pump more efficient (2026)
Quick Answer
To make a heat pump more efficient, focus on the basics first: keep airflow clear, clean or replace filters on schedule, use sensible thermostat settings, and make sure the outdoor unit has space around it. Efficiency also depends heavily on the home itself, so reducing draughts and improving insulation can cut the workload on the heat pump. If performance still seems poor, have a qualified engineer check refrigerant charge, controls and overall system setup.
Overview
A heat pump is most efficient when it can move heat steadily without having to work harder than necessary. In practice, that means three things: good airflow through the indoor and outdoor units, sensible controls, and a home that does not leak heat. Many efficiency problems come from simple issues such as dirty filters, blocked coils, furniture covering vents, or a thermostat being turned up and down too aggressively. Others come from the building, including poor insulation, draughts or badly balanced emitters. The best approach is to start with the safe, homeowner-friendly tasks and only then move to professional checks. Begin by confirming the system is operating as designed, then clean what is meant to be cleaned, clear obstructions, and optimise settings. After that, improve the surrounding conditions by sealing obvious air leaks and making sure radiators, underfloor loops or fan units can release heat properly. If the unit short-cycles, runs constantly without reaching temperature, ices excessively, or energy use suddenly rises, that usually points to a fault or setup issue that needs a trained technician. Done in the right order, these steps improve comfort, reduce wear and can lower running costs without guessing at unsafe adjustments.
Who this is for
Homeowners and tenants responsible for basic maintenance of an air-source or ground-source heat pump, and anyone trying to improve comfort and reduce running costs without carrying out sealed-system repairs.
What you’ll need
- Heat pump user manual or manufacturer instructions
- Replacement air filter if your system uses one
- Vacuum with soft brush attachment or a soft brush
- Cloth for wiping accessible surfaces
- Basic garden tools for clearing vegetation around the outdoor unit
- Torch
- Notebook or phone to record thermostat settings and maintenance dates
- Access to loft hatch, windows and doors if you plan to check insulation and draughts
Before you start
Check what type of heat pump you have and read the user section of the manual first. Turn the system off before touching filters or accessible panels. Do not open sealed refrigerant components or electrical compartments unless you are qualified. If the system is under warranty, confirm which maintenance tasks are allowed for the owner and which must be done by an approved engineer.
Step-by-step
- 1
Confirm the system is in the right mode and set for steady operation
Check that the heat pump is in the intended mode for the season and that the thermostat or controller is using normal scheduled operation rather than frequent manual overrides. For most heat pumps, avoid big temperature swings and repeated high setpoint changes just to 'heat up faster'. If you have weather compensation or similar control features, make sure they are enabled if recommended by the manufacturer or installer.
Why: Heat pumps are generally most efficient when they maintain temperature steadily. Large or frequent setpoint changes can trigger less efficient operation and increase cycling.
- 2
Clean or replace the air filter and clear indoor airflow paths
If your system has a user-serviceable filter, remove it as instructed in the manual and clean or replace it using the manufacturer guidance. Check that supply and return grilles, indoor fan units and radiators are not blocked by furniture, curtains, storage or dust build-up.
Why: Restricted airflow makes the system work harder to move the same amount of heat, which reduces efficiency and can affect comfort and defrost performance.
- 3
Inspect and gently clean accessible coils and fan areas
With power off, look at accessible indoor and outdoor coil surfaces and fan inlets for leaves, fluff, dust and debris. Remove loose material carefully with a soft brush or vacuum if the manual allows it. Do not bend fins, force water into electrical parts or use harsh cleaners unless specifically approved by the manufacturer.
Why: Dirty heat-exchange surfaces reduce the system's ability to absorb and release heat, so the compressor has to run longer for the same result.
- 4
Keep the outdoor unit clear and unobstructed
Make sure the outdoor unit has open space around it, with no stacked items, dense planting or snow and leaf build-up restricting air movement. Keep the base area draining freely and check that discharge air can escape without recirculating straight back into the unit. If snow or ice is present, clear it only in ways the manufacturer permits.
Why: The outdoor unit needs strong, unobstructed airflow to collect or reject heat. Blocked airflow is one of the most common causes of poor efficiency.
- 5
Optimise the heat delivery side inside the home
If your system uses radiators, underfloor heating or fan units, make sure they can release heat properly. Open emitters that are meant to stay open, bleed radiators if your heating system requires it and you know how to do it safely, and avoid shutting off too many rooms. If some rooms overheat while others stay cool, note the pattern for later balancing by a professional.
Why: A heat pump can only work efficiently if the heat it produces can move into the home evenly. Poor circulation or badly balanced emitters can force longer run times and higher operating temperatures.
- 6
Reduce the building's heat loss
Seal obvious draughts around doors, windows and service penetrations, close uncontrolled gaps where practical, and improve insulation where feasible, especially in areas already identified as weak. Use extractor fans sensibly and avoid leaving windows open for long periods while heating is on.
Why: The less heat the home loses, the less work the heat pump has to do. Building improvements often deliver bigger efficiency gains than control tweaks alone.
- 7
Book routine professional servicing and performance checks
Arrange servicing in line with the manufacturer guidance and any warranty conditions. Ask the engineer to check system controls, sensors, airflow or water flow, defrost operation, refrigerant circuit condition, and whether the system appears correctly set up for the property. If your electricity use or comfort has changed suddenly, mention when the change started.
Why: Some of the biggest efficiency losses come from faults or setup issues that are not visible to the owner, such as control errors, low airflow, sensor problems or sealed-system issues.
Why this works
A heat pump does not create heat in the same way as a direct electric heater; it moves heat from one place to another. Its efficiency depends on how easily it can transfer that heat. Clean coils, good airflow, correct controls and low heat loss all reduce the effort needed from the compressor, which is the main energy user in the system.
Common mistakes to avoid
- Turning the thermostat sharply up and down instead of using stable settings
- Ignoring dirty filters or blocked grilles
- Crowding the outdoor unit with bins, plants or stored items
- Closing too many radiators, vents or internal doors and then wondering why the system struggles
- Trying to wash coils or open sealed components without following the manufacturer instructions
- Assuming the heat pump is at fault when the real issue is insulation or draughts
Troubleshooting
System runs for a long time but rooms still feel cool
Check filters, vents, emitter settings and thermostat schedule first. Then look for blocked outdoor airflow and obvious draughts. If those are fine, arrange a professional performance check.
Outdoor unit ices heavily or seems to defrost poorly
Make sure airflow is not blocked by debris, snow or nearby objects and that drainage around the base is clear. If icing remains abnormal, contact a qualified engineer.
Energy use has risen suddenly
Compare current settings with previous ones, inspect filters and airflow, and note any recent weather changes or building changes. If there is no obvious cause, have the system serviced.
Some rooms are too warm and others too cold
Check whether emitters are blocked or shut, and whether doors and vents are affecting airflow. If the pattern persists, ask for system balancing or control adjustments.
Heat pump starts and stops too often
Avoid frequent manual thermostat changes and check whether airflow is restricted. Persistent short cycling needs professional diagnosis.
Compare your options
Basic owner maintenance
Best for: Improving efficiency with simple, low-risk tasks
Pros: Quick to do, low cost, often fixes common airflow problems
Cons: Will not resolve setup faults, refrigerant issues or deeper system design problems
Controls optimisation
Best for: Homes where the system works but comfort or running pattern seems inefficient
Pros: Can improve comfort and reduce waste without major physical changes
Cons: Settings vary by system and poor adjustments can make performance worse
Home fabric improvements
Best for: Draughty or poorly insulated homes
Pros: Reduces heat demand and benefits comfort beyond the heat pump itself
Cons: May require more planning and upfront spend than maintenance alone
Professional service and recommissioning
Best for: Persistent poor performance or suspected faults
Pros: Addresses hidden issues and can restore design performance
Cons: Costs more than DIY checks and depends on access to a qualified engineer
| Option | Best for | Pros | Cons |
|---|---|---|---|
| Basic owner maintenance | Improving efficiency with simple, low-risk tasks | Quick to do, low cost, often fixes common airflow problems | Will not resolve setup faults, refrigerant issues or deeper system design problems |
| Controls optimisation | Homes where the system works but comfort or running pattern seems inefficient | Can improve comfort and reduce waste without major physical changes | Settings vary by system and poor adjustments can make performance worse |
| Home fabric improvements | Draughty or poorly insulated homes | Reduces heat demand and benefits comfort beyond the heat pump itself | May require more planning and upfront spend than maintenance alone |
| Professional service and recommissioning | Persistent poor performance or suspected faults | Addresses hidden issues and can restore design performance | Costs more than DIY checks and depends on access to a qualified engineer |
Alternatives
- If your current system is fundamentally undersized or badly installed, replacement or redesign may be more effective than repeated minor tweaks
- If heating demand is very high because of poor insulation, prioritising fabric upgrades may deliver better returns than altering heat pump settings alone
Pro tips
- Keep a simple log of filter changes, service visits and controller settings so you can spot what actually improves performance
- Photograph the controller before changing settings so you can revert if needed
- If your system has multiple modes, use the manual terminology rather than guessing what a symbol means
- After clearing airflow problems, give the system time to settle before deciding whether efficiency has improved
Safety notes
- Isolate power as instructed before removing filters or accessible covers
- Do not touch refrigerant pipework joints, sealed components or internal electrical parts unless you are qualified
- Take care around fan blades, sharp coil fins and wet or icy ground near the outdoor unit
- Use only cleaning methods approved in the manual to avoid damaging coatings, fins or electronics
Legal & regulatory notes
Work on refrigerant circuits and many electrical repairs must be carried out by appropriately qualified professionals and may be subject to local regulatory requirements. Warranty terms may also require servicing by approved technicians and documented maintenance.
What this guide does not cover: This guide covers practical owner-level ways to improve heat pump efficiency. It does not provide model-specific control programming, sealed refrigerant work, electrical repair instructions, detailed hydronic balancing procedures or formal system design calculations.
Cost considerations
The cheapest gains usually come from maintenance and airflow improvements, while insulation and professional recommissioning cost more but can have wider benefits. Running-cost savings vary with climate, electricity tariff, control settings, heat demand and the condition of the system.
Prefer to hire a professional?
If this job is beyond a confident DIY — or the work needs to be done by a licensed professional — you can find a verified heating & cooling specialist through Trade Directory (tradedirectory.co.nz), New Zealand's directory of real, verified trade businesses. Compare local tradespeople, read their details and request quotes before you commit.
Find a heating & cooling specialist on Trade DirectoryFrequently asked questions
Should I turn my heat pump off when I leave the house?+
Usually it is better to use programmed setbacks rather than switching it fully off for short absences, because heat pumps often work best at maintaining a steady temperature. Follow the manufacturer guidance for your controls.
Do higher thermostat settings make a heat pump warm the house faster?+
Not in the way many people expect. A much higher setting does not usually make the unit produce heat more efficiently; it mainly tells the system to run longer or harder, which can increase energy use.
How often should I clean the filter?+
Follow the schedule in your manual and inspect it more often during heavy use, dusty conditions or if you have pets. A visibly dirty filter should not be left in place.
Is it normal for the outdoor unit to frost up sometimes?+
Some frosting can be normal in cold, damp conditions, and heat pumps usually manage this through defrost cycles. Persistent heavy ice or poor recovery after defrost needs checking.
Can I improve efficiency just by changing settings?+
Sometimes, but not always. Settings help most when the system is otherwise healthy and the home is reasonably airtight and insulated. Dirty filters, blocked airflow or faults will still hold efficiency back.
Core efficiency practices change slowly, but control features, warranty requirements and local regulatory rules can vary by model and location.