Common problems with Chimneys and how to solve them.

Every chimney is different, even if they are built in the same way they will still behave differently due to other factors such as air and pressure, as such, a cure for a problem in one chimney will not always work in another. Here are some common problems with chimneys and ideas on how you might solve them. It is always advisable for you to seek the help of an expert to diagnose and cure chimney problems such as a HETAS registered company.. 


If you are based outside our local area you can find your local HETAS registered company at their website hetas.co.uk 

Smoking:

• Have the chimney swept including the flue connecting the stove to the chimney. 
• Check for soot build up on the baffle plate inside the stove 
• Check the joints in the stove; these can be resealed with fire cement. 
• Check the rope seals around the doors and glass and replace if missing or frayed. 
• Ensure that your chimney is high enough to give a good draw. 
• Your chimney may need to be lined. 
• Check that your chimney pot or cowl are big enough and that you are using the right type for your chimney 
• There may be strong winds, which could cause a pressure difference outside your house causing air to be sucked down the chimney; a chimney fan could help this. 
• Is there enough ventilation for the stove?Current building regs state that for each KW above 5, 550 sq mm of ventilation is required this can be in the form of an airbrick or a ventilator near to thestove. 

Downdraft:

• Check that the chimney has a clear passage of air over it, if it does not terminate high enough or becomes covered by trees etc this can cause downdraft. 
• Check the cowl and if necessary fit an anti downdraft cowl. 

What is downdraft?
Downdraft is recognised by the chimney smoking and is caused by air blowing back down the chimney, this will result in smoke puffing out of the stove.There can be other reasons for smoking chimney, which may be confused with downdraft. Smoking caused by downdraft will not be continuous. Downdraft is often caused when a chimney is not high enough or when the chimney is shadowed by high buildings or trees which will effect the wind flow; remember that wind can travel from all directions so downdraft may only occur for you on certain days when the wind blows in a particular direction.

Sometimes raising the height of the chimney can help or adding a taller chimney pot, another solution could be to add an anti downdraft cowl.

Low heat or slow to start:

• Have the chimney swept including the flue pipe. 
• Check for soot build up on the baffle plate. 
• If you have fitted a damper to the stove check it is operating correctly. 
• If the stove goes into a large chimney area which is uninsulated then it may require lining. 

Runs to fast or wont shut down:

• Check the stove joints and reseal with fire cement if necessary 
• Check the rope seals and change if frayed or missing 
• Check for any cracks in the stove 
• Fit a flue damper to the stove (only if it is safe to do so) 

Tar build up

• Burn dry seasoned wood less than 20% moisture content, or slow burn with coal on a multifuel stove. 
• Use an anti tar powder between sweeps 
• Line chimney often chimneys that are large inside contain lots of tar because the flue gasses cool and harden before they can be released.

What's the best kind of wood to burn?

What kind of wood should I burn?

Alder:  low in heat and does not burn for long,
Apple:  Great It bums slowly and steadily when dry, with little flame, but good for heat.
Ash:  The best wood for burning; has both flame and heat, and will bum when green, but burns best when dry.
Beech:  Nearly as good as ash, and only fair when green. If it has a fault, it will shoot embers a long way.
Birch:  good for heat but it burns quickly. A nice smell.
Cedar:  Good when dry. It gives little flame but lots of heat, a lovely scent.
Cherry:  Burns slowly, with good heat. Another wood with the advantage of a nice scent. 
Chestnut. OK. Will spark. Small flame and heating power.
Douglas Fir:  Poor. Little flame or heat.
Elder:   Average . Very smoky. Quick burner, with not much heat.
Elm:  Commonly sold for fuel. To bum well it needs to be dried for two years. Even then it will smoke.
Hazel:  Good.
Holly:  Good, will burn when green, but best when dried for a season.
Hornbeam:  A rival to beech.
Laburnum:  A poisonous tree, foul smoke, taints food, best never used.
Larch:  Crackles, nice scent, and fairly good for heat.
Laurel:  Gives a brilliant flame.
Lime:  Poor. Burns with dull flame.
Maple:  Good.
Oak:  New oak gives a poor flame and the smoke is foul, but dry old oak is excellent for heat, burning slowly and steadily until whole log collapses into cigar-like ash.
Pear:  Good heat and a good scent.
Pine:  Bums with a wonderful flame, but often spits. The resinous Weymouth pine has a lovely scent and a cheerful blue flame.
Plane:  Burns nicely, but will spark if very dry.
Plum:  Good heat and smell.
Poplar:  Very bad.
Rhododendron:  The thick old stems burn well. 
Robinia (Acacia):  Burns slowly, with good heat, but with foul smoke. 
Spruce:  Burns very quickly and with lots of sparks.
Sycamore:  Burns with a good flame, with medium heat. But do not use green.
Thorn:  Very good. Slow burning, with good heat and little smoke.
Walnut:  Good, and so is the scent..
Willow:  Poor. It must be dry to use, and then it burns slowly, with little flame. Will spark.
Yew:  Among the best. Burns slowly, with strong heat, and the scent is nice.


Need a Woodburner? Great deals on Woodburning and Multifuel stoves

Wood Fuel Guide

Wood is a major source of renewable heat energy and if burned efficiently, it produces virtually no smoke. Using wood from sustainably managed trees reduces net CO2 production compared to using fossil fuels. So heating with wood significantly reduces our reliance on fossil fuels while reducing CO2 emissions.

Select a fuel type that matches the appliance instructions and warranty to ensure that you stay safe: then the appliance will provide a long and reliable service. Log burners can use dry hardwood or soft-wood logs - less than 25% moisture content is the usual requirement.

Where possible, use locally produced wood as it improves fuel security and encourages local

community.  

Logs - Factors to Consider

1. Moisture content—Dry wood (well seasoned) burns better than wet wood (green logs). Wet wood is much less efficient and if you can get them to light at all, logs that are not dry provide a fire that

smoulders and creates lots of tars and smoke. These tars can be corrosive, potentially damaging the

lining of the flue and increasing the danger of a chimney fire. Wet logs will tend to blacken glass in stoves even if the stove is designed to keep the glass clean. When trying to burn wet wood, the fire has to boil off the water before any heat is provided to the room. Well seasoned logs can have twice the heating value of green logs.

Only burn dry wood, either by buying it dry, or by seasoning green logs. Dry in a sunny, well aired space for one or two summers, keeping rain off in the winter. Radial cracks and bark that comes off easily

suggest well-seasoned wood; better still, check with a moisture meter. First

calibrate the meter and then measure a freshly split surface to get the best reading.

2. Wood density—When buying logs, the seller should advise whether they are from hardwood or softwood tree species (or mixed). The general difference is that hardwoods tend to be denser than softwoods. This means that a tonne of hardwood logs would occupy a smaller space than a tonne of softwood logs.

Denser wood tends to burn for a longer period of time meaning fewer “top ups” are required to keep a log stove burning for a given length of time. Since the heating value is approximately proportional to the weight of the wood (for the same moisture content), hardwood logs are typically priced as more expensive than softwoods when bought by volume.

3. Contamination—Ensure that your firewood is not contaminated e.g. with paint or preservatives. Treated wood should never be used in a stove because it could produce harmful gas emissions which may affect health. Burning

contaminated wood is also more likely to corrode flue lining and damage the chimney as well.

Other Fuel Types

Briquettes - typically made from sawdust, a by-product from industrial manufacturing processes. The sawdust is compressed and lignin in the wood can be softened, allowing it to act as a natural binder, giving a reformed log size product. Briquettes are dense and this reduces the amount of storage space required. They are clean to handle and easy to take home in ‘ready to burn’ retail packs. Usually, they can be used as an alternative to firewood. The burning characteristics are different and the settings on a stove may need to be adjusted to get the best out of the fuel. Start by using less briquette fuel than you would firewood, as a briquette can produce more heat. They can usually be broken into smaller pieces to suit requirements.

Wood chip - Good quality chip should be processed to the European specification (EN 14961-4) which states guidance on both particle size and moisture content. Adherence to this will mean that the chips will help the appliance (especially domestic sized boilers) work at their optimum efficiency and reliability. Typical wood chip from a tree surgeon is too wet and variable in chip size for most appliances.

Wood pellets - are typically comprised from the same raw materials as a Briquette. Pellets are much smaller, with the European standard (EN 14961-2) providing diameter options of 6mm or 8mm. Pellets are widely used for biomass boilers, however pellet stoves are increasingly more commonplace in the market. Poor quality pellets that have too much dust are prone to crumbling, whilst over-long pellets will clog the feed mechanism.

Look for the HETAS logo when buying your wood fuel.

More Information

The Biomass Energy Centre provides a great directory of wood fuel producers in the UK, including all HETAS certified wood fuel producers, along with other related advice.

Finding a Wood Fuel Supplier

HETAS certify producers for their consistency of producing a good product with suitable description. See the HETAS fuel quality webpage for listings. When purchasing, check-out the following:  

Is the fuel the right type and size for your stove?

For firewood users, are the logs green or seasoned? (is there a specified moisture content?) Consider how much space you need if drying your logs - you need space for at least one winter, preferably two).

Some log suppliers supply by the “load” - what does this mean? Request a volume measurement in cubic metres.

Where is the wood fuel coming from? Is the woodland sustainably managed, and reasonably nearby? (have they been imported?)

Hardwood or Softwood logs?

Does the supplier offer a stacking service?

Quality Assured Fuel

HETAS certify producers that meet high standards in the production of firewood, briquettes, wood chip and pellets. 

More Information

The Biomass Energy Centre provides a great directory of wood fuel producers in the UK, including all HETAS certified wood fuel producers, along with other related advice.

Information provided by HETAS The official body for solid fuel and biomass heating systems, fuels and services hetas.co.uk

North Wales Stoves Ltd is a HETAS registered retailer so you can buy your wood fuel with confidence....

Blazers wood fuel logs are a HETAS registered fuel producing less than 8% moisture, Blazers are available to buy from our showroom in Betws Yn Rhos call us on 01745 822344 begin_of_the_skype_highlighting            01745 822344      end_of_the_skype_highlighting begin_of_the_skype_highlighting            01745 822344 begin_of_the_skype_highlighting            01745 822344      end_of_the_skype_highlighting      end_of_the_skype_highlighting for our latest prices and special offers or visit our showroom.

 Directions to our showroom