A heat pump in a typical UK home uses anything from 2,500 to 4,500kWh of electricity every year. Usage is, of course, seasonal, with cold winter days seeing as much as 15kWh of electricity consumed, and warmer summer days ranging from 1kWh to 3kWh. At any given moment, the pump draws between 0.4kW and 5kW depending on how hard it’s working.
For many people, these numbers may be lower than expected. That’s because a heat pump moves heat around rather than generate it. For every unit of electricity it uses, a well-designed heat pump system can deliver three to four units of heat. So even though the pump runs on electricity, it uses far less than the amount of heat it puts into your home.
In this blog, we look at exactly how much electricity a heat pump uses and what can make that figure fall or rise.
| Timescale | Approximate electricity use |
| Per hour | 0.4-5kWh |
| Per day (winter) | 7-15kWh |
| Per day (summer) | 1-3kWh |
| Per month (winter) | 300-450kWh |
| Per year | 2,500-4,500kWh |
These figures are based on a typical 3-bed house with an annual heat demand of 10,000kWh. Larger homes, or those with poor insulation, will use more electricity.
A heat pump in a typical home will use roughly 2,500 to 4,500kWh a year. Daily, this means that you could see up to 15kWh on a cold winter day but less than 3kWh on a warmer, sunnier day when the pump only heats water.
These figures should not be taken as absolute. They are based on the assumed use for a typical three-bed home that is reasonably insulated and has an annual heat demand of around 10,000kWh. Energy consumption in your own home depends on its size and insulation.
A formula helps you to get a rough idea of your own figure.
Most of a heat pump’s electricity use comes between October and March, and you’ll notice that your heat pump does much more work during these colder months as it warms the home and ensures you have hot water. During the summer months, the home does not require heating at all, and if it does, only rarely. So the pump only warms the water rather than the entire home.
No. A 5kW heat pump does not use 5kW of electricity. Kilowatts in relation to heat pumps refer to heat output, not electricity input. This is often where those considering a heat pump get confused, perhaps understandably.
Because a heat pump multiplies the energy it uses, a 5kW unit running at a typical efficiency (3.5 SCOP) draws only about 1.4kW of electricity to provide 5kW of heat. The rest of the warmth is pulled in for free, from outside.
When you shop for a heat pump and see an 8kW, 12kW, or 16kW rating, this is how much heat it can produce, not how much electricity is added to your bill.
A domestic air-source heat pump typically draws between 400 watts to around 5,000 watts when it runs, with larger units at the top of that range.
Modern heat pumps are inverter-driven. This means output fluctuates rather than being shut off and on at full power. On warmer days, the heat pump might use a few hundred watts, then on colder days it will draw considerably more.
Many domestic air pumps will draw between 2 and 15 amps off a standard 230V single-phase supply.
Heat pumps are wired to their own circuit and are protected by a suitably sized breaker for the demand. In large and commercial properties, a three-phase supply is often needed.
In most homes, space heating accounts for most of the heat pump’s electricity use, with hot water making up the rest.
During summer months, when the heating is switched off, the pump is mainly used for hot water. In winter, most of its efforts are put into warming the property.
Several factors determine how much electricity your heat pump will use. The biggest is its efficiency. The more heat your unit can produce per unit of electricity, the less it draws overall.
Compared with direct electric heating, a heat pump uses far less. This can be as much as a third to a quarter of the electricity.
An immersion heater, for example, turns one unit of electricity into one unit of heat. A heat pump, on the other hand, can turn one unit of electricity into three or four units of heat. That means that the typical home we touched upon earlier would take around 10,000kWh of electricity to heat with direct electric heating and only around 2,500kWh with a heat pump.
The most reliable way to know how much electricity your heat pump uses is to measure it. There are a few ways you can do this:
Once you know how many kWh your heat pump uses, working out the cost is easy. Simply multiply your annual electricity use by your unit rate. A pump using 2,857kWh per year on a standard tariff will cost a few hundred pounds a year, and if you select a tariff specifically for heat pumps, you can reduce that even further.
For a deeper dive into costs and comparisons with other heating sources, our guide to heat pump running costs explains what you could expect to spend.
At Sussex Air Conditioning and Heat Pumps, we install MCS-accredited air-source heat pumps throughout East and West Sussex for homes and businesses. Utilising our years of experience, we’ll size a system correctly for your property so it runs on as little electricity as possible. Get your free quote today or call us on 01273 434586 for more information.
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