Whether a heat pump suits your home depends mostly on how well insulated it is and how it’s currently heated. A reasonably well-insulated home with radiators or underfloor heating sized correctly can work very well with a heat pump. A poorly insulated older property with no upgrades planned is a harder fit, at least without some extra work first. There’s no single right answer — it comes down to your specific house.
How an air source heat pump actually works
An air source heat pump doesn’t burn fuel to make heat the way a gas boiler does. Instead, it extracts heat from the outside air — even when it’s cold outside, there’s still usable heat energy present — and uses a refrigerant cycle to concentrate that heat to a useful temperature, which it then feeds into your heating system and hot water.
The key difference from a boiler is that a heat pump works most efficiently delivering heat at a lower temperature over a longer period, rather than blasting out very hot water in short bursts. That’s why radiator sizing and insulation matter so much to how well a heat pump performs in practice.
Croydon’s mix of housing stock
Croydon has a real mix of property types — Victorian and Edwardian terraces, 1930s semis, post-war housing, and newer modern builds. This matters because:
- Older, solid-wall properties (common in parts of Croydon) often have poorer natural insulation unless they’ve been upgraded, which can make a heat pump less efficient unless insulation is improved first
- Cavity wall homes, common in 1930s–1970s housing, are usually a better starting point if the cavity has been insulated
- Newer builds are typically well insulated and often well suited to heat pumps from the outset
Pros of a heat pump
- Lower running emissions — no on-site gas combustion, and increasingly cleaner as the electricity grid decarbonises
- No gas supply required — useful for off-gas-grid properties, though most of Croydon is on the gas network
- Long service life — heat pumps are generally durable when properly installed and maintained
- Quiet operation — modern air source units run considerably quieter than older models
- Works alongside solar PV — can reduce running costs further if you already have or are considering solar panels
Cons and practical considerations
- Upfront cost — heat pumps typically cost more to install than a like-for-like boiler swap
- Outdoor space needed — the outdoor unit needs a suitable spot with clearance, which can be tight on some terraced properties
- Radiator upgrades — many homes need larger radiators (or underfloor heating) to get the best performance, adding to the installation cost
- Insulation matters more — a heat pump exposes any weaknesses in a home’s insulation more than a boiler does, since it runs at lower flow temperatures
- Disruption during install — swapping radiators and running new pipework where needed takes longer than a straight boiler swap
The Boiler Upgrade Scheme
The UK government runs the Boiler Upgrade Scheme, a grant that helps towards the cost of replacing a fossil fuel boiler with a heat pump in England and Wales. The scheme has been running for several years and the eligibility criteria and grant amount are set by the government and reviewed periodically, so it’s worth checking the current government grant amount and eligibility rules directly before budgeting, rather than relying on a figure that may be out of date.
When a heat pump is a strong fit
A heat pump tends to work well when:
- The property has reasonable insulation (loft insulation, and cavity wall insulation where applicable)
- There’s outdoor space for the unit with adequate clearance
- Radiators can be upgraded where needed, or the property has underfloor heating
- You’re planning to stay in the property long enough to benefit from lower running costs over time
When it may not be the right fit yet
A heat pump is a harder sell when:
- The property has solid walls with no insulation upgrades and no plans for any
- There’s very limited outdoor space for the unit
- Budget doesn’t stretch to any radiator upgrades that might be needed
- The existing heating system would need extensive rework to run at lower flow temperatures efficiently
In these cases, it’s often worth tackling insulation improvements first, or considering a hybrid approach, before committing to a full heat pump installation.
Getting a proper assessment
A heat pump is a bigger decision than a straightforward boiler swap, and the right choice genuinely depends on the specifics of your property — its insulation, its current heating system, and the space available outside. A proper site survey and heat loss assessment is the only reliable way to know whether a heat pump will perform well in your home, and what size unit and radiator changes it would need. Eco Flow can talk through the options for your property and give you a fixed quote once a survey has been carried out.