Guide · Costs
Hybrid heat pump cost
Keeping the boiler alongside a heat pump is cheaper up front — with one big catch.
A hybrid heat pump system, where a smaller heat pump works alongside the existing gas boiler, costs £6,000–£10,000 installed in the UK in 2026. It is cheaper than a full retrofit because no cylinder or radiator upgrade is usually needed, but hybrids are not eligible for the £7,500 Boiler Upgrade Scheme grant (GOV.UK, 2026), so the net cost is often higher than going all-electric.
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How a hybrid works
A smaller heat pump (typically 4–6 kW) covers the majority of the heating season. The boiler takes over on the coldest days and, in most configurations, handles hot water. Controls switch between them based on outdoor temperature or relative running cost.
The grant maths
Because hybrids keep a fossil fuel appliance, they fall outside the Boiler Upgrade Scheme. A £8,000 hybrid costs £8,000. A £12,000 full air source retrofit costs £4,500 after the grant. That reversal is why most UK households comparing both options end up going fully electric.
When a hybrid still makes sense
- Large, hard-to-insulate properties where full electrification would need a very large unit.
- Homes with a nearly new boiler that the owner does not want to scrap.
- Properties with electrical supply constraints that block a bigger heat pump.
- Off-plan phased upgrades where insulation work is coming later.
Frequently asked questions
- How much is a hybrid heat pump in the UK?
- £6,000–£10,000 installed in 2026, with no grant available because the gas boiler stays in place.
- Do hybrid heat pumps qualify for the Boiler Upgrade Scheme?
- No. The scheme requires the fossil fuel heating system to be replaced, so hybrid installs are excluded.
- Is a hybrid cheaper to run?
- It depends on the switchover settings. Running the heat pump for most of the season and the boiler only in deep cold is usually the cheapest configuration.
- Boiler Upgrade Scheme — GOV.UK — Official guidance on the £7,500 BUS grant in England and Wales.
- Energy Saving Trust — Heat pump efficiency, running cost and SCOP benchmarks (UK).
- Nesta — How to Heat 28 Million UK Homes — Independent research on heat pump deployment and running costs.
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