Frequently Asked Questions
Before Purchasing a Fireplace
You should never choose a stove solely for it looks and design – there are many other considerations that you need to take into account. To get the most out of your stove, it is important that the stove’s output capacity matches your actual heating needs. If the stove is too powerful, the air supply will be limited, which in turn gives a poorer combustion and results in more soot accumulation in the stove and chimney. In other words, both fuel and stove are used inefficiently. The following are important:
How do you determine what size stove you need?
There are several ways to do this. A very rough guideline is to first, calculate the square metreage of the area to be heated, with assuming a standard ceiling height of 2,7metres.
If your area is partly insulated, or not very tight, then divide your square metres by 10, to get to the kW heating capacity of the correct stove.
If your area is average in insulation, then divide your square metres by 13, to get to the kW heating capacity of the correct stove.
If your area is well insulated, for instance double brick insulated brick walls and double glazing and insulated roof, then divide your square metres by 20, to get to the kW heating capacity of the correct stove.
This is a starting point for you.
Again, please keep in mind that this is a very rough guideline because it does not take into account what part of the country you reside. Heating requirements in Mesina will vary from Sutherland.
That is why you should discuss this with your Dovre Dealer in much more detail. Every home is a little different and because of the variation in floor plans from home to home, heat will flow differently thus affecting comfort levels. And, not everyone wants a Dovre stove for primary heat. Many choose to have their stove a secondary source of heat, and for the aesthetics that a wood fire brings to the hearth.
Holiday home or permanent residence?
In most cases, heating needs are less for holiday homes. For permanent residence, stove size depends on individual needs.
Primary or secondary heating?
If the stove is to be used as the main source of heat in the home, you should choose one that matches the size of your house – preferably a convection stove, since these distribute heat optimally. If the stove is only to be used as a secondary source of heat, on the other hand, e.g. to heat up a living room, then a smaller stove is the right choice.
Houses vary enormously in how well they are insulated, and if your house is poorly insulated, you should choose a slightly bigger stove.
Dovre’s stoves are designed around your particular fuel needs, and therefore you are not restricted to a particular type of fuel. Hard wood and anthracite are suitable if the stove is intended as the main source of heat, for example, or if it is going to be used as a supplement to other forms of heating. If you only want to create a cozy atmosphere, wood or gas is the obvious choice. The most common types of fuel are briefly described below:
Wood is an economical and environment-friendly resource. Even if you have to buy the wood, e.g. from a forester, it is still cheaper that burning oil and gas or electric heating. You have to make up the fire more often with wood that with other types of fuel, of course, but wood gives quicker and more pleasant warmth.
Anthracite are a good supplementary fuel if, for example, you want to keep the fire in all night.
Anthracite and similar oil-based products are suitable for use in stoves with a cast iron grate. This fuel has an extremely high calorific value, and is perfect if you only want to make up the fire less often. Use a Dovre coal insert for the built-in fireplace.
L.P. Gas is convenient to use and gives a uniform heating throughout the heating period.
A well-functioning chimney is crucial to a successful installation. In principle, the chimney acts as the stove’s motor. If it does not have the right draught, the stove will not function optimally. Modern stoves make greater demands on, for example, draught and chimney conditions, than older stoves which use traditional burning principles.
All stoves must be installed in accordance with building regulations. For stoves installed in single-family homes, semi-detached, terraced houses, summer houses, etc. the rules and regulations of the small home apply. You, your technical consultant or builder, are responsible for ensuring that the regulations are complied with. It is therefore a good idea to get in touch with the local council, who can tell you all you need to know.
Today all Dovre stoves are characterized as closed fireplaces with the regulations that applies.
Dovre stoves can be connected to chimneys where other solid fuel closed fireplaces, e.g. another wood stove is also connected, provided that each appliance uses its own flue pipe.
The Chimney’s draught is created by the difference between the high temperature inside the chimney and the colder temperature outside.
A good draught is obtained:
* When there is a big difference between the inside and outside temperatures
* In clear weather
* When the chimney has the right height
Poor draught results:
* When the temperature difference is too small, e.g. due to a poorly insulated chimney
* When the outside temperature is too high, e.g. in summer
* If the chimney is not high enough, so that it is sheltered by tall trees or rooftops. In such cases, there is a big danger of return smoke
* When false air gets into the chimney, e.g. through cracks in the joints
Connecting the stove to the chimney does not require authorizations, but if you want help, talk to your dealer about it. Dovre stoves can be connected to either brick or steel chimneys.
Most Dovre stoves can be connected from the top or back. A flue sleeve is bricked into the wall and the flue inserted into this and sealed using ceramic packing cord. The advantage of a top connection is that you also get the extra heat given off by the flue gasses in the stove pipe.
As previously mentioned, Dovre stoves can be connected from the top or back, but with a steel chimney, the connection is mostly from the top.
Talk to your dealer about steel chimneys and installation.
After Purchasing a Fireplace
The glass in my stove is full of soot – what could be wrong?
Soot will appear on the glass if the combustion temperature is too low or if the lighting period is too short. When lighting the stove a lot of air must be supplied to warm up the chimney. Open the riddling grate and the air controls. If necessary, open the door a bit to supply as much air as possible. When the kindling have turned into embers, dry wood is supplied. Plenty of air must still be supplied. Besides, wet wood or poor draft conditions might cause sooty glass. Ask your Chimney sweep to measure the draft in your chimney.
How do I remove soot from the door glass?
You can clean the glass using Dovre Glass Cleanser or any other glass cleaner. This must be done when the stove is cold. If heavy soot built-ups appear, use treble ammonia water to clean the glass. Soot may appear on the glass if the combustion temperature is too low or if the air controls are used incorrectly. Don’t use any scorchers which might damage the glass surface.
How often should the stove be cleaned for soot and ashes?
The stove needs to be cleaned up at least once a year. But naturally depending on how much the stove is used. The baffle is removed from the stove and cleaned up. Note that the stove must be cold when cleaned up. Remove all residue and ash from the inside. If the baffle is fixed clean on top of the baffle with something like a vacuum cleaner. The outside surface will be kept well if vacuum cleaned with a soft nozzle. If necessary wipe the stove with a moist cloth, but only when the stove is completely cold. Be careful when choosing cleaning materials as the paint may be damaged by acid or ammonia.
How do I clean the surface of a painted stove?
The surface will be kept well if vacuum cleaned with a soft nozzle. If necessary wipe the stove with a moist cloth, but only when the stove is completely cold. Be careful when choosing cleaning materials as the paint may be damaged by acid. If necessary, use mild detergent or brown soap. The painted surface may in the course of time get a grey tinge; but the stove can easily be freshened up with a special heat-resistant spray-paint, which can be bought from your dealer. The stove must dry 24 hours before being used again. Some fumes will be given off by the paint. Ventilate the room during this phase.
There is soot in my chimney; how did that happen?
If the temperature is too low you might experience tarry soot or creosote in your chimney. The combustion temperature will be too low if not enough air is supplied compared to the amount of wood. Tarry soot is easily recognized as a brown sticky coat. Supply more secondary air to increase the temperature. A stove pipe thermometer placed on the lower part of the flue pipe will indicate if the air supply is correct. The flue gas temperature must be approx. 250º C. If the flue gas temperature is considerably lower, tarry soot may be created in the chimney. If the flue gas temperature exceeds 250 – 300º C, the inside parts might be superheated. Superheating can damage the inside parts of your stove.
Smoke is coming out into my living room when I open the stove door. How do I avoid that?
Do not open the door before the wood is burned all the way down to embers. When opening the door, a lot of cold air will get in contact with the flames which may cause smoke inconveniences. If you for some reason have to open the door before the wood is burned to embers, this has to be done carefully. Let the door stand on a 2cm gap for a moment before opening it completely. Another reason might be poor draft conditions. A chimney sweeper is able to measure the draft.
There is not enough draft in the chimney. What can I do?
If the chimney is too low, not well insulated or has a leak, you may experience draft problems. Let the chimney sweep take a look at it and measure the draft. It is essential that the chimney is well heated during the lighting period. Use a lot of kindling and 1-2 fire starters. Open the grate and the door a bit if necessary. When the kindling has burned to embers, 2-3 pieces of dry wood are added. Plenty of air is still supplied.
What kind of chimney is the best?
Steel chimney or a well-insulated brick chimney. They both have to be min. 4 meters to get an optimum draft in the chimney. Besides, the height of the chimney you have to make sure that the chimney is free from the roof ridge to avoid down-draft. The diameter of the chimney must be between 150-200 mm. If a brick chimney is not insulated the diameter must be more that 200 mm which, however, will also reduce the draft conditions. We therefore recommend an insulated chimney. It is a good idea to ask a chimney sweeper for advice.
How high should the chimney be?
The chimney must be at least 4 meters from the pipe connection to get an optimum draft. However, it also depends on how much draft the individual stove demands. The chimney demands 3-5 Pascal’s per meter depending on wind conditions and the surroundings (trees, buildings).
How should the diameter of the chimney be?
The diameter should be at least 150 mm and ought not to be more that 200 mm as this will reduce the temperature of the smoke and thereby cause poor draft conditions.
How long should the horizontal flue pipe from the stove to the chimney be?
The flue pipe from the stove to the chimney must be as short as possible to avoid cooling down the smoke. If the smoke does not have the right temperature, it may cause poor draft conditions and smoke inconveniences. Only one elbow ought to be connected to the stove as the smoke will face too much resistance.
Are the draft conditions different if the stove is fitted with a rear flue exit instead of a top rear flue exit?
We have not been able to measure any difference in the draft conditions between a stove fitted with a top flue exit instead of a rear flue exit. However, judging from experience a top flue exit is an advantage if the draft conditions are not optimum as the smoke will face less resistance and draft and smoke inconveniences can therefore be avoided. Most stoves are fitted with a top flue exit.
How often should a chimney sweep check the chimney?
Once or several times a year depending on your municipal requirements. It is recommendable that you clean up the stove once or twice a year yourself. It is essential to remove soot and ashes on the baffle as it will make the baffle last longer.
The glass in my stove has cracked. What has happened and can I replace it myself?
Cracks on the glass may happen due to bumps from the wood. Besides, impurities may be found in the wood such as pebbles that may hit the glass during the combustion. If the glass has cracked, it naturally has to be replaced – Dovre has the necessary fibre rope for glass that can be bought at any Dovre dealer.
The bricks in my stove have cracked. Are they to be replaced?
Cracks in the bricks may happen due to bumps from the wood. There is no need to replace the bricks even though they are cracked. They do still insulate the fire chamber. The purpose of the bricks is to insulate the fire chamber to increase the combustion temperature. However, if they start crumbling, the insulation disappears. This may damage the cast iron and they do in this case have to be replaced.
How far from inflammable material must the stove be installed?
Stoves must be installed at least 50 cm from inflammable material. If the stove is to be installed up against an non-inflammable wall, you can decide the distance yourself. Dovre recommends 10-15 cm for cleaning purposes.
Can I install my stove to a chimney where an oil burner already is installed?
Yes, as long as the height difference between the two installations is at least 25 cm. You are allowed to install two stoves to the same chimney if the height difference is min. 25 cm. However, do never install a stove to a chimney where a gas furnace already is installed. Use separate flue pipe stacks for each appliance.
Can I install my stove myself?
Yes, as long as the local building requirements are followed. The clearance distances to combustible materials are to be kept. It may be a good idea to ask the chimney sweep for advice.
What types of wood are preferable?
The heavy, hard types of wood, such as, acacia, blue gam and hardekool have a high heating value whereas the heating value of pine is low. Wet wood may cause smoke and air inconveniences. Timber refuse can be used if it is not impregnated or bleached with salt water or acid. Well seasoned wood is thus preferably.
What are the advantages of radiant stoves?
Radiant stoves are fitted with one side panel which means that the stove emits a faster heat. Radiant stoves gets warmer on the surfaces than convection stoves which means the heat is more concentrated around the stove. Radiant stoves are often used in summer cottages where fast heat often is needed.
What are the advantages of convection stoves?
Convection stoves are fitted with an extra side panel. The distance between the two side panels is approx. 15cm. Cold air is led from below the stove and up between the two side panels, spreading pre-heated air into the room. The clearance distances to furniture in connection with convector stoves are shorter than to radiant stoves as the heat emission is not as hard. Besides, the heat is spread more evenly.
How many square meters is 1 kW?
1 kW is more or less equal to 10-20 m² depending on the insulation of the house. It is recommendable to choose a smaller stove as the combustion will get cleaner if you fire hard in a small stove instead of slumber use in a large stove.
How much ash should be left at the bottom of the stove?
At least 2-3 cm ashes are recommended for wood burning stoves only. The ashes insulate the base the same way as the bricks insulate the sides. The combustion temperature will get higher and the combustion clean. Besides, the ashes protect the riddling grate. Note when the ash can is emptied, the ashes must be kept in the ash bucket a few days until the ashes are completely free from embers.
The baffle has burned to pieces. Why?
The baffle is a consumable part that has to be replaced as required. Dovre’s cast iron stoves have a quite long lifetime if the consumable parts are replaced when they are worn down. This might happen if too much primary air is supplied through the riddling grate. If too much primary air is supplied through the riddling grate, the temperature in the fire chamber will be quite high – much like a forge. Another reason might be a layer of ashes and soot on the baffle. This insulates the heat which then might burn through the baffle. Soot and ashes on the baffle must be removed 1-2 a year. Use a steel nozzle, or vacuum cleaner.
Can stove dressing be used on Dovre stoves?
Stove dressing cannot be used on Dovre stoves. Besides, the surface of painted stoves will be unsightly and flaky if stove dressing is used. Stove dressing can be used on old stoves that are sandblasted or grinded down. Painted stoves must be painted with a Dovre spray paint and enamelled stoves must be cleaned with distilled water and soft soap.
How to light a fire
- Before lighting the fire, open a window or ventilator on the windward side slightly to pressurise the room, ensuring that the fireplace will not smoke and to provide sufficient air for combustion.
li> Place two or three layers of paper balls on the grate. These are made by scrunching up individual sheets of old newspaper into ball shapes.
- Place some kindling (dry and finely cut small pieces and splinters of wood) or fragments of wax and paraffin fire lighters at random on top of the paper balls.
- Pile one or two layers of anthracite or slightly larger pieces of wood on top of the paper balls. Don’t pack to tight.
- Open the damper to maximise the intake of air from the room. Once the fire is well on its way it is usually best to close the damper partially so as to reduce the amount of heat escaping up the chimney.
- Light the paper balls in three of four randomly spaced places.
- To assist the burning paper in heating up and igniting the coals or logs, you can use fire bellows (which increases the amount of oxygen required for the combustion process).
- Once the fire is lit, gradually add more layers of anthracite or larger logs, taking care not to apply too much too soon, or you will dampen down the fire and possibly extinguish it.
- When further refueling is required it may be necessary to open the damper again.
- Use dry, seasoned wood. The moisture content of wood directly affects the way the appliance operates. Well seasoned dry wood (cut, split and stacked under cover for at least 12 months) will give best results and least problems.
- Wet or green wood not only creates more work for you due to the increased weight when carrying it, but most importantly will not burn efficiently. You will receive less heat from wet/green wood as energy is used to evaporate the moisture from the wood.
- Ideally, seasoned wood should contain 12% to 22% moisture. Wood with a moisture content of more than 22% will require a great deal more air to light, heat output will be cut dramatically, and soot and creosote will build up in your flue system. In addition, you may have smoke warting back into the room. If you hear your wood sizzle or you can see moisture bubbling from the ends of the logs placed on a hot fire, your wood is too wet.
- If the fuel you are burning tends to splatter, the use of a Home Fires fire screen is recommended. Low grade anthracite tends to splatter a lot. Use only high grade anthracite and use large nuts of anthracite or coke.
- Never use wood of the pine family. Pine contains a very high amount of resin. This can cause dangerous soot build-up and which can overheat your fireplace.
- You may use anthracite in your fireplace. Buy the best grade of anthracite in order to prevent splattering and to produce more heat.
- Do NOT use coal or briquettes.
Which fire is best for me?
When choosing a gas or wood-fired stove its capacity is a determining factor. Many people are unaware that an average living room space only requires 3 to 4 kilowatts (kW) to heat it. This is especially true in today’s well-insulated homes and, given the fact that many homes already have more than one heating source; the fire in the living room is often just used for additional heating.
Yet consumers often go for a too high a capacity, with the risk that they subsequently use the fire sparingly or can only burn at a low degree, otherwise it would become too hot for the room. With wood-fired stoves and heaters this results in poor combustion, blackened glass and high emissions. With gas fires, it particularly means you don’t get to enjoy the lovely flame effect these fires have to offer.
Calculating the capacity needed to heat the space you have in mind is very easy. The graph shows the capacities indicated in kWs. The space to be heated is indicated in cubic meters (m3). The number of cubic meters is determined by multiplying the length, width and height of the space. You can then read the capacity you require at the intersection of one of the three lines. Which of these three lines you select depends on the degree to which your home is insulated.
- Well insulated
- Is double-glazed
- Has floor and wall insulation
- Is reasonably insulated
- Has minimal double glazing
- Has minimal floor and wall insulation
- Poorly insulated
- Has no double glazing
- Has no floor and wall insulation
Open and closed combustion
In addition to this, the choice between open or closed combustion is equally important. ‘Open combustion’ may lead you to think we are talking about an open fire, without a glass front, but this isn’t the case. Open combustion is the name given to the system whereby air is extracted from the room in which the fire or heater is positioned, and where the flue gases are removed via a single flue.
What types of stoves are there?
Wood fires and stoves always have an open combustion system. It is important to know when choosing your wood fire or stove that good ventilation in the home is a prerequisite. When a home is well-ventilated you can always install a wood fire or stove. In exceptional circumstances, such as homes with a so-called ‘Balance Ventilation System’ there are fires and stoves with exterior air feeds. An increasing number of fires and stoves are equipped with such an exterior air feed, or offer this as extra. With this system the combustion air is extracted from outdoors. Please take into account that with a wood firer, the flue must always go upwards, through the roof and outdoors, and must even reach above roof ridge height.
On the other hand with gas fires and stoves, there is the choice of closed combustion, whereby the requisite combustion air is directly extracted from outside and the flue gases are removed via the same flue. Such extraction can, in many cases, be simply fed through the outside wall or roof. This means you have more flexibility in the exact positioning of your fire. As the system extracts oxygen from outdoors and not from the room where the stove is placed, the system is also ideally suited to the modern, well-insulated and mechanically ventilated home. In the case of gas fires and, you will always be advised to opt for closed combustion. However, if you wish to connect a gas fire or stove to an existing chimney with a diameter of less than 150 mm, then open combustion may well be an option as this requires a smaller flue.
Having read this, you will no doubt conclude that in making your final choice of fire, you will need personal, expert advice. And of course you will want to see the range of models you are keen on in person, and maybe even see them in action.
As such, we recommend you consult with a Home Fires fireplace specialist. Home Fires has fantastic showrooms in which a range of fires and stoves are presented. Their expertise advice will enable them to provide you with personalized, bespoke advice. In addition to which, many dealers can draw a sketch for you, helping you to visualize the fire or stove in your home. You will be able to discuss your stove fitting wishes too, as the dealer can provide these too.