How do wood burning stoves with back boilers work?
Wood burning stoves cover a range of technologies, from old fashioned pot belly wood stoves through to state-of-the-art wood pellet burning stoves.
Wood burning stoves burn logs, wood pellets or wood chips to power central heating and hot water boilers.
The back boiler works in the same way as the traditional back boiler connected to an open fire.
Wood burners typically burn logs, but more sophisticated versions burn wood pellets and will usually feature automatic ignition and pellet feeding systems.
How much energy will a wood burning stove with back boiler generate?
Depending on type of system installed, wood burning stoves with back boilers can be used in support of your existing heating system or, in many cases, to fully power your heating and hot water.
The typical system can generate 10 - 15kW of energy, which is more than enough to provide hot water and heating throughout your home.
Log burners Vs pellet burners
The advantages of log burners:
- Log burning stoves provide a great way to dispose of (and recover energy from) surplus wood and timber.
- If you are lucky enough to have your own wood source you could become self-sufficient in providing heating and hot water to your home.
- Log burners tend to be less expensive than pellet burners.
- Log burners require less maintenance than the more complicated pellet burners.
- Log burners can provide that special cosy feeling inside just like the traditional open log fire.
- Contemporary ceramic wood burning stoves can provide an attractive feature in a living room.
The advantages of pellet burners:
- They are highly efficient.
- Wood-pellet stoves provide for greater convenience and control than a log burner, with the majority of pellet burners featuring automatic ignition.
- Pellet burners offer greater control over the temperature of the room in which the stove is situated.
- Pellets are denser than logs, which makes them easier to transport and reduces the amount of storage space needed.
- Pellet burners need to be topped up less often than log burners as they are denser and will usually have an integral hopper.
- Pellet burners are cleaner, produce less ash and are generally easier to look after than log burners.
Are there any problems with wood burning stoves?
- You will need space to store the wood, logs or pellets.
- The market for wood fuel is still in its infancy in the UK. The cost and quality of wood fuel can fluctuate greatly.
- Stoves need to be manually fed, log burners in particular will require regular 'topping up'.
- You will either need to upgrade your existing chimney for fume extraction or install a separate flue
- The chimney / flue will require regular cleaning
- If you are using your own wood source, the wood will need to be "seasoned". This means it needs to be stored to dry it out (Freshly cut trees have a high moisture content which makes them less suitable as a wood fuel).
What consents will I need before fitting a wood-fuelled heating system?
Planning permission is not normally needed when installing a wood-fuelled heating system in a house if the work is all internal.
If the installation requires a flue outside it will not need planning permission if the conditions outlined below are met:
Flues on the rear or side elevation of the building are allowed to a maximum of one metre above the highest part of the roof.
If the building is listed or in a designated area it is advisable to check with your local planning authority before a flue is fitted. Listed Building Consent is also likely to be needed for internal alterations.
In a conservation area or in a World Heritage site the flue should not be fitted on the principal or side elevation if it would be visible from a highway.
Wood burning stoves will have to comply with the Building Regulations. Your installer should take into account factors such as ventilation, noise and general safety. The installer should be suitably qualified, preferably one who belongs to either the Microgeneration Certification Scheme or a relevant Competent Person Scheme.
What should I be looking for when employing a wood burner installer?
Local Authority Building Control (LABC) advises on 2 options for employing an installer:
Option 1: Employ a Competent Persons Scheme certified installer
Some installation companies are registered with the Government’s Competent Persons Scheme. This allows them to install and ‘self-certify’ the stove without having to make a formal application to the Council under the Building Regulations.
The largest Competent Persons Scheme provider is HETAS. Make sure the installer provides you with a certificate of compliance at the end of the job. You will need this certificate should you come to sell your property.
Option 2: Employ a knowledgeable trades person and have the job inspected by your Council's Building Control Service
If you appoint a trades person who is not part of a relevant Competent Persons Scheme, then you will need to submit a Building Regulations application to your local Council. The Council's Building Control Officer will then come out and inspect the job to ensure that the wood burner has been installed safely. If satisfied with the work, the Council's Building Control Officer will issue a completion certificate.
As with Option 1, you will need this certificate should you come to sell your property, so do not pay the final bill to your installer until you have this piece of paper in your hands.
How much does a wood burning stove with back boiler cost?
Expect to pay around £4,000 for a good quality, pellet burning wood burner with back boiler. This typical cost includes installation and the cost of upgrades to your existing chimney or the cost of installing a flue.
Wood pellets will cost up to £200 per tonne. Expect to burn at least 10 tonnes of pellets a year.
For log burners, the price of logs fluctuates widely, but you may be in the fortunate position of being able to source your wood fuel for free.
Wood burners are viewed by many energy analysts as a smart long term investment. Using local wood fuel to heat your home will reduce your reliance on oil, gas and electricity, prices of which are projected to continue to rise over the coming years.
Are there any grants or other funding support available to help pay for wood burning stoves with back boilers?
The Green Deal scheme may be able to help you pay for the upfront costs of the installation through Green Deal financing. The installation costs will then be paid back over time, with interest, through your electricity bill.
The UK Government's "Renewable Heat Premium Scheme" offers grants of up to £2,000 for the installation of wood burners in locations where there is no mains gas heating available.
The soon to be launched "Renewable Heat Incentive" will pay you to produce heat from a wood burning stoves with back boilers.
If you have a reliable, local log, wood chip or wood pellet supplier, or even better, if you have you own wood supply and space where the wood can be dried out, then a wood burning stove with back boiler could dramatically reduce your energy bills.
If you have no access to mains gas heating, you may be able to access grant funding under the Renewable Heat Premium Scheme to help may for the installation of your wood burning stove with back boiler.
A top tip from the Energy Saving Trust website is that a wood burning stove with back boiler and solar heating are a great combination as the stove can heat your home and provide hot water in winter and the solar can heat your hot water in the summer when no central heating is required.
Need further advice? For more advice on the best wood fuel system for your needs check out the Forestry Commission Website. For installation advice check out the Local Authority Building Control (LABC) Technical Guide on Wood Burning Stoves. Alternatively why don't you join our discussion forum