Gas Safe Registered
WhatsApp Us
Boiler Guide

Biomass Boiler

Low-carbon heating fuelled by wood pellets, chips, or logs.

A biomass boiler burns organic fuel — most commonly wood pellets, wood chips, or logs — to heat your home and water. Biomass heating is considered low-carbon because the CO₂ released during combustion is approximately equal to what the wood absorbed while growing.

Typical Cost
£10,000–£25,000 installed (highly variable by system size and fuel type)
Install Time
3–5 days
Efficiency
85–95% depending on boiler model and fuel quality

How Does a Biomass Boiler Work?

Wood pellets or chips are stored in a hopper or store and fed automatically into the boiler's combustion chamber via an auger. Logs are loaded manually. The burning fuel heats water that circulates through radiators and a hot water cylinder. Ash is produced and must be removed periodically. Pellet systems can be largely automatic, requiring only occasional refuelling of the hopper.

Pros & Cons

Advantages

  • Considered carbon-neutral — CO₂ released equals CO₂ absorbed during wood's growth
  • Eligible for the Domestic Renewable Heat Incentive (RHI) payments in some schemes
  • Wood fuel is often cheaper per kWh than oil or LPG
  • Suitable for off-grid rural properties
  • Modern automated pellet boilers are very convenient

Disadvantages

  • High upfront cost — significantly more than a gas boiler
  • Requires significant storage space for fuel (pellets, chips, or logs)
  • Produces ash — requires regular emptying (weekly to monthly depending on use)
  • Not suitable for urban or suburban properties with limited space
  • Pellet/chip delivery logistics can be complex in remote areas
  • Complexity is higher than gas boilers — more components to maintain

Best For

  • Rural properties with space for a fuel store
  • Homes in areas with good wood fuel supply chains
  • Environmentally-conscious homeowners wanting low-carbon heating
  • Properties with high heat demand where fuel cost savings justify the investment

Not Ideal For

  • Urban or suburban homes with limited outdoor space
  • Properties where convenience and low maintenance are the top priorities
  • Households with small heating demands where payback periods are very long

What Is a Biomass Boiler?

A biomass boiler is a heating system that burns organic biological material — most commonly wood in the form of pellets, chips, or logs — to generate heat for central heating and hot water. Biomass is classified as a renewable energy source because the carbon dioxide released during combustion is considered to be offset by the carbon absorbed by the trees and plants during their growth.

Types of Biomass Boiler

There are three main types of biomass boiler available in the UK:

  • Wood pellet boilers — the most popular automated option. Compressed wood pellets are stored in a hopper and automatically fed into the boiler. Very convenient once set up.
  • Wood chip boilers — typically used for larger properties or commercial applications. Cheaper fuel than pellets but requires more storage space and a larger delivery infrastructure.
  • Log (cordwood) boilers — also known as gasification boilers. Logs are manually loaded in batches and burned at high temperature. Often the most affordable option but requires the most manual effort.

Running Costs and Incentives

Wood pellets and chips are typically cheaper per kWh than oil or LPG, which can make biomass heating cost-effective over the medium to long term once the high installation cost is amortised. Previous UK government incentive schemes (the Domestic RHI) have made biomass particularly attractive — check current OFGEM guidance for up-to-date eligibility information.

Is Biomass Heating Right for Your Property?

Biomass heating is best suited to larger rural properties — farms, country houses, or large village homes — that have space for a fuel store and a good local supply of wood fuel. It is not practical for urban or suburban homes with small gardens and no delivery access.

Ready to Get a Price for a Biomass Boiler?

Use our instant calculator to get a fixed price — or speak directly to one of our Gas Safe engineers in Corby.