The quick answer
- Heat pumps are generally better for most UK homes. Cheaper to run, less maintenance, no fuel storage
- Biomass suits rural homes with existing wood supply and storage space
- Heat pump: £2,500–7,500 after the BUS grant vs biomass: £10,000–18,000 (no current grant)
- Running costs are similar: £800–1,200 (heat pump) vs £800–1,400 (biomass) — the biomass running costs guide shows the pellet maths
The short answer
For most UK homes the heat pump wins, mainly on upfront cost: £2,500–£7,500 after the Boiler Upgrade Scheme against £10,000–£18,000 for biomass, which no longer qualifies for a grant. Running costs are close, at £800–£1,200 against £800–£1,400.
Biomass also brings fuel storage, ash removal and £200–£400 a year of maintenance. Over 15 years in a typical 3-bed off-grid home the totals come out at roughly £22,250 and £35,000. Biomass makes sense where you already have a wood supply and somewhere to keep it.
Side-by-side comparison
| Factor | Heat Pump | Biomass Boiler |
|---|---|---|
| Upfront cost (after grants) | £2,500–7,500 | £10,000–18,000 |
| Annual running cost | £800–1,200 | £800–1,400 |
| Efficiency | COP 2.5–4.0 | 85–93% |
| Fuel needed | Electricity only | Wood pellets, chips, or logs |
| Fuel storage | None | Hopper or store required |
| Annual maintenance | £100–200 | £200–400 + ash removal |
| Carbon emissions | Low (grid-dependent) | Low (carbon-neutral fuel) |
| Noise | 40–60 dB outdoors | Some noise from feed mechanism |
| Space required | 1m² outdoors | Large indoor room + fuel store |
| Government grant | £7,500 (BUS) | None currently |
| Lifespan | 15–20 years | 15–20 years |
Total cost of ownership: 15 years
For a typical 3-bed off-grid home replacing oil heating:
| Cost element | Heat Pump | Biomass |
|---|---|---|
| Installation | £5,000 | £14,000 |
| Running costs × 15 | £15,000 | £16,500 |
| Maintenance × 15 | £2,250 | £4,500 |
| 15-year total | £22,250 | £35,000 |
Most of that £12,750 gap is the grant
The £5,000 installation figure assumes the £7,500 Boiler Upgrade Scheme grant, which biomass no longer qualifies for. Whether you actually get it depends on the property and its EPC. Our BUS grant checker works that out in about a minute, and the running costs guide shows where the £15,000 comes from.
Check your grant eligibility →
Heat pump advantages
- Much lower upfront cost thanks to the £7,500 BUS grant
- No fuel storage or delivery. Runs on electricity
- Minimal maintenance, annual service, no ash, no chimney sweeping
- No planning headaches, Permitted Development, no flue regulations
- Can provide cooling in summer (some models)
- Pairs with solar panels to further reduce running costs
Biomass advantages
- Works during power cuts (log-fired models), heat pump doesn't
- Carbon-neutral fuel. Wood is a renewable resource
- High heat output, suits poorly insulated or large rural properties
- Familiar technology. Works like a traditional boiler
- Free fuel if you have woodland. Dramatically reduces running costs
- No outdoor unit, suits properties with no suitable outdoor space
Biomass no longer has grant support
The BUS scheme (2022 onwards) does not cover biomass boilers, only heat pumps. The old RHI scheme has closed. This makes heat pumps significantly cheaper to install than biomass for most homes.
When biomass may still make sense
- You have your own woodland, free or near-free fuel changes the maths entirely
- Very large, poorly insulated rural property, heat pumps struggle with high flow temperatures (though less than people assume, see heat pumps in older homes)
- No reliable electricity supply, remote locations with unreliable grid connection
- Existing biomass infrastructure. Already have fuel store and flue
- You enjoy the process. Some people prefer managing a wood fuel supply
Frequently asked questions
Is biomass carbon neutral?
In theory yes, trees absorb CO₂ as they grow, which is released when burned. In practice, supply chain emissions (processing, transport) mean biomass isn't fully carbon neutral, but it's far better than fossil fuels.
Can I combine a heat pump with biomass?
Yes. Hybrid systems can use a heat pump for base load and biomass for peak demand. However, this doubles installation cost and complexity. Rarely justified for domestic properties.
Do biomass boilers smell?
Pellet boilers produce minimal smell. Log boilers produce more smoke and require regular attention. Properly maintained systems should not produce visible smoke from the flue.
If you go the biomass route, two cheap things are worth having: a firewood moisture meter (logs above 20% moisture waste fuel and gum up the flue) and a carbon monoxide alarm, which building regulations require whenever a new solid-fuel appliance goes in, and which Scotland requires in every home that has one.
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