If you're considering installing a heat pump, one of the first questions you'll probably ask is, "How much will it cost me to run?"
The good news is that modern heat pumps are one of the most efficient ways to heat and cool your home. While every house is different, understanding how they work and what affects running costs can help you keep your power bill under control.
How Much Electricity Does a Heat Pump Use?
A common misconception is that a 5kW heat pump uses 5kW of electricity every hour.
It doesn't.
The "5kW" refers to the amount of heating the unit can produce, not the amount of electricity it consumes. Thanks to modern inverter technology, a 5kW heat pump often only uses around 1.2–1.6kW of electricity while maintaining temperature.
That makes heat pumps significantly cheaper to run than portable electric heaters.
Typical Running Costs
The figures below are approximate and depend on electricity prices, outdoor temperature, insulation, and thermostat settings.
| Heat Pump Size | Approximate Running Cost |
|---|---|
| 2.5–3.5kW | 20–40 cents per hour |
| 5kW | 35–65 cents per hour |
| 7–8kW | 55–90 cents per hour |
Once your home reaches the desired temperature, the heat pump usually reduces power consumption because it only needs to maintain the temperature.
What Affects Running Costs?
Several factors make a much bigger difference than the size of the unit.
Insulation
A well-insulated home holds warmth much longer. Ceiling insulation, wall insulation and double glazing can dramatically reduce heating costs.
Thermostat Setting
Setting your heat pump to 30°C won't heat your home faster—it simply makes the unit run harder for longer.
Most homes are comfortable between 20°C and 22°C.
Dirty Filters
Blocked filters reduce airflow, forcing the unit to work harder and consume more electricity.
Cleaning filters every month or two can improve efficiency.
Damaged Pipe Insulation
One often-overlooked issue is damaged insulation on the refrigerant pipes outside your home.
The insulation protects the pipes from losing energy. If it has deteriorated due to weather or birds, your heat pump becomes less efficient and costs more to operate.
Replacing damaged insulation is inexpensive and can improve performance.
House Design
Homes with:
- Large windows
- High ceilings
- Poor insulation
- Open-plan layouts
naturally require more heating than smaller, insulated homes.
Heat Pump vs Electric Heater
For the same amount of heat produced:
- Heat pump: Most efficient
- Oil column heater: Moderate
- Fan heater: Higher running cost
- Bar heater: Highest running cost
Heat pumps typically produce three to five times more heat than the electricity they consume.
Tips for Reducing Running Costs
- Clean filters regularly.
- Keep doors and windows closed while heating.
- Use Auto mode rather than maximum fan speed.
- Set the temperature around 20–22°C.
- Have the unit professionally serviced every year.
- Check outdoor pipe insulation remains intact.
Thinking About a New Heat Pump?
Every home is different. Choosing the correct size and installation location makes a much bigger difference to running costs than simply buying the biggest unit available.
Our team can assess your home and recommend the most efficient solution for your budget.
If you're in Whangārei, Kerikeri or the surrounding areas, explore our full range of heat pump services or contact Gibson Electric for friendly advice and a no-obligation quote.