Air Source Heat Pumps: Let’s Stop Believing The Hype
Just bought a new home? Renovating your current place? Or just curious about all the noise online? Let’s skip the marketing fluff — here is exactly what an engineer actually thinks about air source heat pumps versus a reliable gas combi boiler.
Should you get an air source heat pump over a gas combi boiler?
My honest opinion? Hell no. You’ve probably been told that you’ll magically save thousands a year in bills and blah blah blah. Don’t believe the hype. Heat pumps are heavily misunderstood by consumers, and a shocking number of installers out there are completely clueless on how to actually design and set them up correctly.
Ambient warmth is not the same as a blast of real heat
An air source heat pump emits what they call “ambient heat.” Instead of the rapid, intense blast of heat you’re used to getting from a traditional gas boiler, a heat pump gives you a slight, constant warmth in the room.
Why is this relevant? Well, if your home is poorly insulated, you can wave a permanent goodbye to any actual heat you had. When a property leaks heat, that electric pump has to struggle and run flat-out 24/7 to compensate for the loss. And because electricity per unit costs way more than gas in the UK, your winter energy bills will absolutely skyrocket if your house isn’t completely airtight.
A combi boiler is small, hidden and simple. An ASHP is not.
Let’s look at the physical reality side by side.
Bulky & exposed outdoors
Compact & hidden away
An ASHP looks an absolute state bolted to the side of your home. It takes up valuable driveway or garden room, needs massive, visible pipes running across your brickwork that have to be heavily lagged, and requires extra holes drilled through your property just to route the new connections.
Compare that to a standard combi boiler. A combi only needs a single flue hole through the wall, a tiny pipe for the condensate line, and a microscopic 15mm hole for the pressure relief valve. That’s it. Everything else is hidden away out of sight. Why would you want to place a massive, delicate box twice the size of a boiler outside your house where it’s completely susceptible to accidental damage, weather, or vandalism?
Gas boilers are not being banned tomorrow
The biggest trick salespeople use to scare you is telling you that gas boilers are being banned tomorrow. Let’s set the record straight: there is no immediate ban for existing households.
- 93% efficiency: Modern gas combis are absolute engineering masterpieces, hitting an incredible 93% efficiency rating.
- Proven, existing network: They run on a bulletproof, existing gas network that has safely heated the UK for generations.
- Future-facing design: The industry is already adapting, designing modern boilers to accept cleaner gas blends to keep our infrastructure future-proof as technology moves forward.
What the paused hydrogen trials actually mean for you
You might have heard about “hydrogen-ready” boilers. The government actually planned to test 100% hydrogen networks in local villages, but they recently paused and cancelled those trials because they realised the national infrastructure just isn’t ready to scale it up yet.
But here is what that actually means for you: it proves they can’t just switch off the gas network overnight. Gas is going to be around for a very long time, and you don’t need to panic-buy an electric system out of fear.
Air source heat pump vs gas boiler — FAQ
Do air source heat pumps work in the UK climate?
Yes, but only well when the property has been properly insulated and the radiators or underfloor heating have been correctly sized for lower flow temperatures. In an older, draughty property they typically struggle to keep up with demand.
Are gas boilers being banned?
No. There is currently no ban on repairing, servicing or replacing an existing gas boiler like-for-like in an existing home. Proposed changes have historically focused on new-build properties only.
Is an air source heat pump cheaper to run than gas?
It depends entirely on your insulation, radiator sizing, and electricity tariff. In a well-insulated, correctly designed system it can be competitive. In a poorly insulated older property, running costs are often higher than an equivalent gas combi.
How much space does an ASHP outdoor unit take up?
Most domestic units require dedicated ground or wall space roughly the size of a large suitcase to a small wardrobe, plus clearance for airflow, drainage and access — considerably more external footprint than a combi boiler flue.
Can I keep my existing gas boiler serviced instead?
Yes. A well-maintained modern combi boiler serviced annually can safely and efficiently run for well over a decade. Our fixed-price annual service is £79.
Protect your cash flow. Stay in control.
Here is the bottom line, and this is being said to save your bank account from complete devastation: do not let aggressive sales pitches brainwash you into ripping out a working gas system for a glorified outdoor fridge.
If you own a standard, traditional home, slapping a low-temperature heat pump onto an uninsulated property is financial suicide. You will pay a fortune upfront, your house will feel like a lukewarm cave, and your electricity bill will bleed you dry.
Stick to your guns. Keep your hyper-efficient, 93% gas boiler maintained, serviced, and running. Let the new-build developers play guinea pig with experimental heating setups. Your job is to protect your cash flow, keep your family warm, and stay in control of your own property. Play it smart and ignore the hype.