The Real Advantages
Air source heat pumps have matured enormously in recent years. The current generation of R290 units — like the Vaillant aroTHERM Plus we install — operate efficiently in temperatures as low as -22°C, produce hot water up to 75°C, and run quietly enough to meet even the tightest planning noise limits.
Key advantages:
- Lower running costs — A COP of 3.5+ means roughly 6–7p per kWh of heat, cheaper than gas.
- £7,500–£9,000 BUS grant — Slashes upfront cost dramatically.
- 0% VAT — On both equipment and installation.
- No gas supply needed — Ideal for off-gas rural properties.
- Works with existing radiators — When properly designed for lower flow temperatures.
- Pairs brilliantly with solar — Free daytime electricity powers your heating.
The Honest Disadvantages
We are installers who believe in honesty. Here are the genuine challenges:
- Higher upfront cost — Even after the grant, a heat pump costs more to install than a replacement gas boiler. The payback period is typically 5–8 years.
- Needs good design — A poorly designed system will underperform and disappoint. This is why we do room-by-room heat loss surveys, not quick estimates.
- Some radiator upgrades may be needed — Heat pumps work best at lower flow temperatures, which means you may need larger or additional radiators. We assess this during the survey.
- Outdoor unit requires space — You need about 1m² of outdoor space with good airflow. Planning permission is rarely needed (permitted development), but noise regulations must be met.
- Defrost cycles — In very cold weather, the unit periodically defrosts, which is normal but can cause concern if you are not expecting it.
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The Design Factor
The single biggest factor in whether you love or hate your heat pump is how well it was designed. A Heat Geek-trained engineer will:
- Calculate heat loss for every room individually
- Design for the lowest possible flow temperature
- Size the cylinder correctly for your hot water demand
- Set weather compensation curves accurately
- Commission the system properly
This is why our customers consistently report comfort levels they never achieved with their old boiler. The heat pump itself is just a box — it is the engineering behind it that makes the difference.
Is an Air Source Heat Pump Right for Your Home?
Most UK homes can work with a heat pump. The best candidates are:
- Detached or semi-detached properties with outdoor space
- Homes with some insulation (even basic cavity wall and loft)
- Properties currently using oil, LPG, or electric heating (biggest savings)
- Homes where the owner plans to stay for 5+ years
If you are unsure, our survey will give you a clear answer — and if a heat pump is not right for your property, we will tell you honestly.
Frequently asked questions
The honest ones are a higher upfront cost than a boiler (offset by the £7,500–£9,000 grant), the need for good design, possible radiator upsizing, and about 1m² of outdoor space. None are dealbreakers when the system is designed properly.
Often yes. In our experience 30–40% of radiators can stay, 30–40% need upsizing to a double panel, and a few benefit from a fan-assisted unit. We calculate this room by room rather than guessing.
For most homes, yes — lower running costs than oil, LPG and electric heating, a large grant, 0% VAT and a 20-year-plus lifespan. The biggest single factor in whether you love it is the quality of the design and commissioning.
A quality R290 unit like the Vaillant aroTHERM Plus has an expected life of 20 years or more with an annual service — significantly longer than the 10–15 years typical of a gas or oil boiler.
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Start with a free, no-obligation online estimate. When you’re ready to go further, book your £250 home survey — fully refunded when you go ahead with your installation.