Chimney fires are a problem
- choose an appropriate fuel for your appliance and burn it as efficiently as possible.
- keep the chimney warm.
- inspect and clean the flues and chimney at regular intervals.
Damp/unseasoned logs can very quickly create a fire hazard in any chimney – particularly if they are burned slowly in a closed stove. The frequent use of household (“bituminous”) coal in a closed stove can likewise generate high volumes of soot. Therefore make a special effort to season your firewood thoroughly before you burn it. (To see a useful technique for doing this click here). If you burn solid fuel, avoid household coal. You’ll find smokeless fuels are far more satisfactory.
A warm chimney is far less prone to fouling up than a cold one. Therefore chimneys contained within the body of the house work best and those on the end of a building – particularly when fully exposed to the weather – have a built-in disadavantage. In the latter case, it may be possible to boost flue-temperatures by lining the flue with a low-mass flexible liner back-filled with an insulating filler material. (Click here for a discussion of internal/external chimney placement)
You should sweep your chimney ‘as often as is necessary’. There is no fixed rule about this since much will depend upon the frequency of use, type of appliance, type of fuels used – etc. If in doubt, call the sweep in sooner rather than later and consult him on his findings. If your useage pattern is fairly consistent it should become fairly easy to judge the intervals at which cleaning is necessary.
Deflector plate - frequent replacement necessary
A central heating stove does far more work than a ‘dry’ stove that is simply heating one room so it is unsurprising that deflector plates tend to burn out much faster in boilered stoves. All the more reason to choose your fuel carefully when you want to keep a battery of radiators hot for hours at a stretch. Smokeless fuel is by far the best choice in this situation. You should aim to create a fire with plenty of heart in it and even, radiant output. This means keeping the airflow through the stove under tight control and not over-running the stove. If you’re burning wood only, click here to see the right approach and here to see the wrong approach. If you’re burning solid fuel or a ‘mixture’ of solid fuel and wood click here to see the right approach and here to see the wrong approach.
Door glass - cracked
Door seals - gumming up problems
Enamel - chipped
Firebricks - frequent replacement necessary
Fracture - a stove panel has cracked
Fuel consumption is excessive
Other factors include use of unseasoned wood. The moisture content in logs has huge impact on the actual amount of fuel you have to burn for a given output as is illustrated here.
You may also be expecting too much of your wood if you are trying to obtain sustained high-outputs from a central-heating stove. The burning characteristics of wood are not well suited to driving high-output boilers in modestly proportioned domestic heating appliances. Switching to a smokeless grade of fuel (Like Homefire or Phurnacite) may well solve your problems.
Finally, take a hard look at your installation. A deeply recessed stove is operating at a massive disadvantage and may only be delivering a fraction of its output to the surrounding air. A properly designed and insulated convector-box can overcome this difficulty. To learn more click here.
Fumes coming into the room
You may also want to check that there is no physical blockage in your stove – caused for instance by a badly deformed deflector plate.
Solid fuel cookers – particularly when run on household coal, can clog rapidly in the flue passages around the oven(s) and should be cleaned at regular intervals.
But in the vast majority of cases, the stove is blameless and the real culprit is your chimney which if it is doing its job properly should be generating enough ‘suck’ to remove all fumes. If it is not, check the flue-connector between your stove and chimney first, since this is often a bottle-neck that clogs up first.
If the problem persists even after you have had the chimney inspected and swept, you may have more serious design/structural problems. Click here for a general discussion on chimneys that may help you trouble-shoot your problem.
Glass keeps going black
The air supply is pre-heated by being passed through a duct in the head of the stove and is then passed over a blade that causes it to spread out and wash the internal surface of the glass.
The door is double-glazed.
The fire-box is lined with insulating fire-bricks in the area of combustion.
The effect of these three techniques is to boost temperatures to a level at which smokeless combustion can take place.
If your glass keeps blacking over, your stove may not be a clean-burn model or the clean-burn features may be poorly implemented. High output boilers virtually obliterate the benefits of a clean-burn design by keeping the combustion temperature down at a level at which even the driest fuelwood is likely to produce some smoke and tar.
The final and most frquent cause of glass blacking up is use of damp/unseasoned wood – particularly in conjunction with long, slow burns.
Glass - how to clean
Grate bars - frequent replacement necessary
The best way to extend the life of your grate bars is to riddle and de-ash at regular intervals. That way the bars are cooled by the air-stream passing through below.
If you let ash levels build up, the cooling effect of the air is lost. In extreme cases you may even ‘submerge’ the bars in a bed of red-hot ash. At these elevated temperatures they will distort and quickly burn out.
Some grades of anthracite generate temperatures high enough to shorten the life of your grate bars. Over-running your stove on almost any fuel will have the same effect – a practice that’s all too common when the stove is a boiler model driving several radiators.
Cheap grate bars of dubious origin will nearly always fail prematurely. Buy only branded spares originating from your stove manufacturer.[Footnote; the above text relates to stoves being fired on solid fuel. If you are burning wood only, you should be burning onto a bed of soft sand or ash – see here – and your grate (if your stove is equipped with one) should last virtually forever.]
Heat output to hot water is inadequate
The burning characteristics of different fuels can have a major bearing on boiler performance. A fuel with a short flame and high radiant output does best. Smokeless fuels and charcoal cannot be beaten, but once again, damp/unseasoned wood is unsatisfactory.
Poor chimney draught – and even excessive chimney draught can upset boiler performance. A poorly designed system may be ‘robbing’ heat due to lengthy pipe-runs, or circulation may be poor. There is too, the possibility that your boiler has been under-specified for the job it has to do.
Thus there are several variables to be examined and in practice a boiler that is actually defective is so rare as to be almost the last thing to consider!
A useful reference point when outputs are in dispute is to do a test-firing with a ‘benchmark’ fuel. If your principle fuel is wood, try burning a quantity of really dry ex-demolition timber. The results may well astound you! If you burn mainly solid fuel, run a test with Homefire. This again will enable you to compare the fuel you are burning against something you can always refer back to.
Heat output to room is inadequate
Radiators are hot but room with stove in it is underheated
Radiators aren't heating up fully
Soot problems. Stove/flues keep clogging up
Slow-burning is another area to review – especially if you are burning damp-unseasoned wood. All stove installations need to be burned up brightly at regular intervals to purge condensate and tars from the flue-ways.
Chimneys on the end of a building – particularly those fully exposed to the weather – soot up far more rapidly than a ‘warm’ chimney accomodated within the main body of the house. Click here for a further discussion on this.
Stove is difficult to light and smokes a lot
Stove is over-heating the room but radiators remain only lukewarm
In the short-term your only option is to attempt to ‘spill’ some of the excess heat from your sitting-room to an adjacent area. In the longer term you should consider replacing you stove with one correctly balanced to your needs.
Stove runs out of control
If the stove is new, a thermostat may be malfunctioning or a damper sticking.
Stoves that are DEFRA exempt are designed to prevent you from shutting them down enough to put the stove into a full slumber and therefore tend to burn quite brightly even when shut down as fully as possible. Stoves that slumber do not burn wood cleanly and thus produce smoke and various deposits which in an a smoke control area, is deemed illegal. However Argyll is not in or near a smoke control area! Also we often suffer from Atlantic gale force winds which can have a considerable impact on a DEFRA exempt stove since you can then find you have much less control over your stove than is ideal when there is a fierce draw due to weather conditions. Depending on the model it is often possible to remove the ‘stop’ in the air control which will enable you to close the stove down more fully. However we recommend you check either with your stove supplier or contact the stove manufacturer directly before making any adjustments.
These are the obvious and cheapest things to check ‘on the ground’.
One other tip to consider if you’re burning wood only is to fill the base of your stove with a bucket full of sand to a level around 25mm (1″) above the grate bars. This kills all air-movement through the heart of the fire and creates a far more stable burning environment. (For a discussion and illustration of the principles involved click here).
If you are in a very exposed location, your chimney draught may exceed the values your stove is designed for. A well-engineered stove built to tight tolerances is better able to resist this problem than a leaky appliance with poorly aligned door-hinges and crude air-valves – and thermostatically controlled appliances are more vulnerable than stoves with robust manual controls.
Often it is best to tackle extreme draught problems at their source. Aerocowls have an excellent track-record for both taming excessive draught and helping to eliminate down-draughts.
Stove won't 'stay in' for long periods
Unpleasant smells coming into the room from the stove
Water keeps boiling
- Airlock somewhere in the system.
- Insufficient rise in the pipes between the appliance and the domestic hot water tank.
- Pipes too small in diameter.
- Pipe runs excessively long.
- Boiler over-specified for the job it is doing.
In the first four cases, the time taken to heat up a tank of cold water may be noticeably slow. You need to call in a plumber – unless you have the competence to tackle the issues yourself.
If the boiler is over-specified for its job, one possible solution is to mask part of it off with some insulating fire-brick using adhesive fire-cement. Another possibility is to dissipate the excess heat through a towel-rail or something similar. The third option of course is to replace the boiler with one matching your needs – though this may involve replacing the entire stove.