Wood Burning, Biomass Stoves or Boilers?

by Solar Cymru.

Wood-fuelled heating systems, also called biomass systems, burn wood pellets, chips or logs to provide warmth in a single room or to power central heating and hot water boilers.

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A stove burns logs or pellets to heat a single room – and may be fitted with a back boiler to provide water heating as well. A boiler burns logs, pellets or chips, and is connected to a central heating and hot water system.

A wood-fuelled biomass boiler could save you up to £880 a year compared to electric heating.

Wood is often cheaper than other heating options, you might benefit from a renewable heat incentive.

It’s also low carbon.

The carbon dioxide emitted when wood is burned is the same amount that was absorbed over the time that the plant was growing. The process is sustainable as long as new plants continue to grow in place of those used for fuel.

A biomass pellet stove will cost around £4,300 including installation. Installing a new log stove will usually cost less than half this, including a new flue or chimney lining.

For boilers, an automatically fed pellet boiler for an average home costs between £9,000 and £21,000, including installation, flue, fuel store and VAT at 5 per cent. Manually fed log boiler systems can be slightly cheaper.

Pellet costs depend mainly on the size and method of delivery. If you have room for a large fuel store that will accept several tonnes of pellets at a time, delivered in bulk by tanker, you can keep the cost down to around £230 per tonne in most parts of the UK.

Logs can be cheaper than pellets, but costs depend on the wood suppliers in your local area, as they cost a lot to transport.

If you have room to store more than a year’s worth of logs you can save money by buying unseasoned logs and letting them season for a year.

If you replace an older gas heating system with a wood-burning system you might save up to £70 a year, but if you are replacing an old electric heating system you could save as much as £880 per year or even more.

You may be able to receive payments for the heat you produce from a wood boiler or a pellet stove with back boiler through the UK government’s Renewable Heat Incentive (RHI).

This technology is an eligible measure under the UK government’s Green Deal which is a financing mechanism that lets people pay for energy-efficiency improvements through savings on their energy bills.

Find out more about support available.

The renewable heat incentive is due to change soon (at the end of June 2015).  Find out how much financial help you can have by contacting us now on 01559 389

Maintenance of woodburning stoves, biomass boilers and woodburners.

Biomass boilers and stoves should be kept clean and swept regularly to remove ash just like an old fashioned fireplace although Ash quantities are generally very low (less than one per cent of fuel volume), but you will still need to empty the ash bin of a wood burning stove or boiler. This is likely to be weekly and never more than once a day. A log fire requires ash removal before every use.

Some even self clean.

Some appliances, particularly boilers, have self-cleaning systems which will collect ash from the combustion grate and the heat exchanger tubes. If there is no automatic ash cleaning mechanism in place the boiler will need to be shut down periodically so that this can be done by hand.

With automatic ash removal and cleaning of the heat exchanger the only other maintenance requirement will be occasional ash removal and an annual maintenance check.

If you have a wood burning stove or boiler the chimney and flue pipe must be swept regularly to remove all soot deposits and prevent blockage.

HETAS recommend that this “should be done at least twice a year, preferably before the heating season to check that the flue has not been blocked by bird’s nests for example and also at the end of the heating season to prevent soot deposits from resting in the chimney during the dormant period”.

Boiler or stove?

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. Stoves are not eligible under the domestic RHI unless it is a pellet stove with a back boiler.

Chips, pellets or logs?

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 have to 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.

Do you have a local fuel supplier?

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

Do you have space?

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.

Do you have somewhere to put the flue?

You will need a flue which 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.

Do you need permission?

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 this guide.

Needless to say, Solar Cymru is a competent installer with a fine pedigree of previous installations of wood burning stoves, fireplaces, solar panels, ground source heat pumps.  Check out or website www.solarcymru.co.uk or contact us directly for any help you’d like for any of the above issues covered in this guide on pencader 01559 389896 during office hours and we will be happy to help.

We’re not here to sell you anything, we’re tradespeople, not salespeople…

About Solar Cymru.

Solar Cymru is a locally run installer of green technologies, based in Pencader West Wales (nr Carmarthen) Solar Cymru install and maintain anything from Solar Panels, to Ground Source heat pumps, wood burning stoves and biomass boilers, rain water collection tanks and much much more…

Solar Cymru have recently been featured on George Clarke Restoration Man, with their stunning restoration of the Old School in Pencader.  More information can be found here.

Solar Cymru is the online arm of Pecs Ltd, a local Master Builder that diversified into green technologies.