Heat pumps are genuinely good technology in the right property and genuinely disappointing in the wrong one. Here is the honest version.
How they work
A heat pump works like a fridge in reverse. It draws thermal energy out of the outside air and moves it into your heating system.
- A fan draws outside air over pipes containing refrigerant
- The refrigerant is compressed, which raises its temperature
- That heat transfers into your heating system
- Hot water circulates through radiators or underfloor heating
A well-designed system produces three to four units of heat for every unit of electricity it uses. That is what makes it far more efficient than any direct electric heating.
What it costs
An air source heat pump for an average home typically runs £8,000 to £15,000 installed.
Additional costs sometimes apply for larger radiators or a hot water cylinder if you are coming from a combi.
What it costs to run
This is where honesty matters, because the answer depends heavily on the design.
Running cost depends on your insulation, your electricity tariff, how well the system was designed, and how you use heating. Heat pump specific tariffs make a real difference.
Compared with oil, LPG or direct electric heating, the savings are significant. Compared with mains gas, running costs are similar or slightly higher at current prices.
The biggest savings are for properties off the gas grid. If you are currently on oil or LPG, a heat pump is usually a straightforwardly good decision.
Is your home suitable?
Good insulation matters. Heat pumps run at lower flow temperatures than a gas boiler, so the house has to hold heat. Loft insulation, cavity fill and double glazing all help considerably.
You need space for the outdoor unit. Roughly the size of a large air conditioning unit, with proper airflow. It cannot be boxed in.
Your heating system needs to suit it. Underfloor heating is ideal. With radiators, some may need upsizing to work at lower temperatures.
You need space for a hot water cylinder. Heat pumps do not work like combis. If you currently have a combi, you will need to find room for a cylinder.
It may not suit poorly insulated properties that cannot easily be upgraded, flats with no outdoor space, listed buildings with restrictions, terraces where noise could affect neighbours, or properties where the electrical supply cannot be upgraded.
The honest pros and cons
In favour: much lower carbon emissions, cheaper to run than oil or LPG, a twenty year plus lifespan with maintenance, no gas safety certificate needed, cooling available on some models, and no 2035 concern.
Against: significant upfront cost, possible radiator upgrades, outdoor space required, some noise, a cylinder needed, insulation quality really matters, and running costs are only comparable with gas rather than better.
Heat pump against gas boiler
| Heat pump | Gas boiler | |
|---|---|---|
| Upfront cost | £8,000 to £15,000 | £1,600 to £5,200 |
| Running costs | Similar or slightly higher | Lower |
| Carbon emissions | Low | Higher |
| Lifespan | 20 years plus | 10 to 15 years |
| Installation disruption | Higher | Lower |
| Future proof | Yes | Until 2035 |
Where we stand
We are LCL Level 3 qualified for both air source and ground source, and qualified in low-temperature heating design, which is the part that actually determines whether a heat pump performs.
We will do a full heat loss survey and tell you honestly whether your property suits one yet. Sometimes the answer is that insulation should come first, and we would rather say that than sell you a system that disappoints.
Frequently asked
Do heat pumps work in cold weather?
Yes. Modern units operate down to around minus fifteen degrees and are standard across Scandinavia, where winters are far harsher than ours. Efficiency drops somewhat in extreme cold but they continue producing heat reliably.
How noisy are they?
Around forty to sixty decibels, comparable to a fridge or quiet conversation. Louder than a gas boiler, so positioning matters, particularly away from bedrooms and near neighbours. There are noise limits that installations must meet.
Will I need new radiators?
Not always. Heat pumps run at lower flow temperatures, so radiators need to be larger to give out the same heat. Modern panel radiators are often adequate and frequently only some need upgrading. We assess this properly rather than assuming.
What maintenance do they need?
An annual service much like a boiler, covering filter cleaning, electrical checks and the water side of the system. Keep the outdoor unit clear of leaves and debris. No gas safety certificate is needed since there is no gas involved.
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