Biomass

Boilers can be used in place of a standard gas or oil boiler to heat radiators for a whole house, and to heat the hot water. Stoves are used to heat a single room, usually in conjunction with other heating systems, but may also have a back boiler to provide hot water.

Chips are used to heat larger buildings or groups of houses.

Pellets are much easier to use and much more controllable than logs. Pellet boilers can run automatically in much the same way that gas or oil boilers operate. Most pellet and chip burners use automatic fuel feeders, which refill them at regular intervals.

Log-burning stoves and boilers must be filled with wood by hand and require considerably more work. You will need a lot of logs to heat a whole house, but they can be cheaper than pellets if you have a good local supply.

Some companies now offer deliveries of pellets anywhere in mainland Britain and Northern Ireland, while the supply of logs is more variable.

If you signed up to the UK Government’s Renewable Heat Incentive, your biomass fuel must be sourced from a supplier on the Biomass Suppliers List. This is a list of suppliers of sustainable biomass fuel. The Renewable Heat Incentive is now closed to new applicants.

You should check whether your fuel supplier is registered on this list before entering into any long-term supply contract.

Wood boilers are larger than gas or oil equivalents and you will need space to store the fuel. This area will need to be somewhere that’s handy for deliveries as well as appropriate for feeding the boiler.

You will need a flue that meets the regulations for wood-burning appliances. This could be a new insulated stainless steel flue pipe or an existing chimney, though chimneys normally need lining to make them safe and legal.

You may not need planning permission, but you should always check. All new wood heating systems have to comply with building regulations, and the best way to ensure this is to use an installer who is a member of a competent person scheme.

For more information on planning permission for biomass, download our guide.

There is increasing concern that burning wood at home can impact local air quality, potentially contributing to serious health problems. This is because burning wood releases certain gases and tiny particles of soot, known as particulate matter, into the air, and there is a risk that these could build up to dangerous levels.

The biggest concern is the use of traditional log stoves, especially if these are used inappropriately. Possible risks include:

• Emissions of particulate matter and nitrogen oxides from the flue, which can contribute to poor air quality in the local area, especially in built up areas where air quality is already a concern.
• Emissions from a log stove directly into people’s homes whenever the stove door is opened for refuelling, potentially creating unhealthy levels of pollution indoors.

Emissions from log stoves can be limited by:

• Choosing a modern, Ecodesign compliant appliance.
• Using a registered competent person to make sure your flue and installation are safe.
• Using dry wood fuel only, to make sure it burns efficiently and completely.
• Sweeping the flue regularly, to help with combustion and make sure any pollutants are drawn out of the house.

Emissions from pellet boilers, pellet stoves and log boilers are generally expected to be lower than from log stoves, and there is less risk of pollutants entering the home directly. However, all wood burning systems will produce some pollution, so you should consider whether it is appropriate to install one if you live in an area with existing air quality issues.

If you live in a smoke control zone, you must use an appliance that is approved for use in these areas. Contact your local authority to check.