As well as enjoying the benefits of two wood burning stoves in his own home, David Ebbs, Technical Sales Support at Specflue has eighteen years experience with the appliances. Here he offers some top tips on the important areas that should be considered when installing a wood burner.
Plan it properly
For most, the ambiance and warmth from an open fire makes a house a home and you need to remember that your customer will look at their stove every day, so decisions should not be made on impulse. The best results come from planning and the initial questions that should be asked include: Where will it stand? (Any stove will need a hearth that projects at least 225mm in front of the stove). Is a classic or modern look stove required? Do they want a single or double door appliance? What colour do they want?
The flue requirements
Where will it go? What is the route and size going to be? Is the stove positioned next to an existing chimney stack that can be utilised, or does a twin wall flue need to pass up through the house, or through the external wall and rise up outside? If you want to use an existing chimney stack, this needs to be checked first, to ensure that it is not being used for something else, and that it is in good enough condition to use with a flue liner. If the stack is going to have a new flexible flue liner installed, you need ensure it is fully swept first. When considering the flue size and route, installers should be aware that many Defra certificated stoves are able to run with a 125mm diameter flue. Sometimes, this is crucial if the installation involves a flexible liner within a tight stack. The flue route has several regulations to consider, such as total height and number of bends. All flue installations should be carried out by a HETAS qualified installer, and a HETAS certificate issued. Remember: A flue should be installed that will last the life of the wood burner, so in most circumstances, it is not a good idea to try and re-use an old flue system.
Decide on the KW size of the wood burner
Sizing correctly is an absolute necessity and most stove manufacturers offer a simple calculation on their websites. An oversized stove can turn the room into a sauna, so the home owner will then only use at half power, causing problems to the flue system. If the stove is replacing an open fire, the home owner needs to remember the difference in efficiencies, as an open fire may reach 10%, whilst most stoves start at around 70% efficiencies. This means they will not need to burn as much fuel to achieve the same degree of warmth in the room.
What about the room
Does the home owner need to make any changes to the room the wood burner sits in? For instance, curtains must not be able to blow and reach the stove. The distance of soft furnishings needs to be checked against the stove manufacturer’s instructions, but allow for a 600mm to 1metre clearance in front of the stove.
All stoves require air for combustion. If the stove is under 5kW, an external air vent is not required under building regulations, but air will still be needed from somewhere else. Even older properties now have draught free double glazing and fully fitted carpets, which eliminate small gaps for air to enter the property. Any air vent for stoves 5kW and above must be HETAS approved, and installed directly on the external wall. Remember this will create a draught from the vent to the stove, so try and position this so the cool air does not travel around the sofa making people’s feet feel cold! If the wood burner is being installed in a kitchen or open plan room with a kitchen extractor, this must be taken into account, as the extractor will draw air from the room. All appliance testing must take place with the extract fan running on full power.
Ensure the data information plate is completed and secured where it is easy to read, either beside the appliance or next to one of the incoming mains services; gas, water or electricity.
Ensure that any termination is approved for the fuel. For instance, a gas terminal would have small mesh and block up with wood and solid fuel burning. An open terminal allows the smoke and products of combustion to clear quickly, but offers no protection from rain or bird and vermin. A rain cap will offer protection from some rain ingress, but creates a barrier to the escape of smoke and gases. Some rain caps also have wood and solid fuel approved mesh to keep out any birds or vermin. If the flue suffers down-draught, then specific terminals can be supplied to help eliminate this problem.
Regular maintenance is essential
The home owner should be given a full demonstration of how to use the appliance and what to check to ensure everything is running as it should. Cleaning should take place every few fires and the flue should be swept at least once a year by a qualified chimney sweep. Failure to keep the sweeping certificates could invalidate house insurance and would invalidate flue warranty. Installers should also explain the stove air vents and air wash vents. Remember: it is now a legal requirement to install a carbon monoxide alarm for each stove and these alarms should be tested regularly and vacuumed out every few weeks.
Some stoves are designed to only burn wood, some are multi-fuel so can burn coal and coke, as well as wood. All wood must be seasoned and have a moisture content not exceeding 20%; a moisture meter can give this moisture content. All coal type multi-fuels must appear on the HETAS approved list. Remember: You should never burn treated or painted wood, household rubbish and plastics in any stove.
Flue and stove thermometers should be used for monitoring the burning temperature, to ensure both safety and maximum fuel efficiency. Burning at a low temperature will increase the likelihood of tar deposits building up inside the flue, which in turn will increase the chances of a chimney fire, as well as making the flue warranty invalid.