Heat Pump vs Boiler - The Honest UK Guide for 2026
Your boiler needs replacing and you are weighing up a like-for-like swap vs making the jump to a heat pump. Here is a thorough, impartial breakdown covering costs, running costs, suitability and the verdict on when each option makes sense.
Full cost comparison
| Gas boiler installation | £2,000-4,500 | No grant available |
| Heat pump installation (air source) | £10,000-18,000 | Before £7,500 BUS grant |
| Heat pump after BUS grant | £2,500-10,500 | England and Wales only |
| Gas boiler annual running cost | £800-1,300/yr | 3-bed semi, Ofgem Q1 2026 rates |
| Heat pump annual running cost | £700-1,200/yr | SCOP 3.5, same property |
| Gas boiler lifespan | 10-15 years | With annual servicing |
| Heat pump lifespan | 20-25 years | Ground loops 50+ years |
| Annual CO2: gas boiler | ~2,400 kg | 3-bed semi, 12,000 kWh demand |
| Annual CO2: heat pump | ~650 kg | Same property, SCOP 3.5 |
When a new boiler still makes sense
Despite the BUS grant making heat pumps increasingly attractive, there are genuine scenarios where a new gas boiler is the right decision:
- Boiler has broken in winter and you need heat immediately. A heat pump takes 4-8 weeks from survey to installation.
- Planning to sell within 3 years. Payback periods of 8-15 years mean you may not recoup the cost difference at sale.
- Property genuinely unsuitable - e.g. high-rise flat with no outdoor unit location, listed building with planning restrictions.
- Budget is tight and the remaining post-grant cost (which could still be £5,000-10,000) is not manageable.
When a heat pump is the better long-term choice
- You heat with oil or LPG. Running cost savings of £500-1,000/year make payback compelling, and there is no gas network to stay on.
- You plan to stay 10+ years. The longer lifespan and running cost savings compound significantly over time.
- You are adding solar PV. Solar panels and a heat pump is a powerful combination - your solar electricity directly powers the heat pump during daylight hours.
- You want to future-proof. New gas boilers are being phased out for new builds. The direction of travel is clear.
Not sure which is right for you?
Use our running cost calculator with your own heating figures, or check BUS grant eligibility in under a minute.
Frequently asked questions
Important disclaimer
heatpumpcompared.co.uk is editorially independent and not affiliated with any heat pump manufacturer or installer. We do not provide heating advice. Prices, specifications, SCOP ratings and grant amounts are correct as of April 2026 but are subject to change. Always commission a professional heat loss survey before purchasing a heat pump system.