What causes glass to crack/break on my stove?

The following are the causes of stove glass cracked:

  • Impact Damage – If the glass is impacted by a piece of fuel sticking out of the firebox or by a stone in the fuel, a small chip can be created on the glass which over time (through repeated heating & cooling) can grow and will eventually cause the glass to crack.
  • Glass Fixings too tight – As the glass grows in size slightly when heated, if the glass screws are over tightened it can cause damage to the glass surface which can cause it to crack. It is recommended to fit the screws until hand tight and then turn the screws back approximately a quarter turn.

What causes webbing (hairline cracks) on stove glass?

The damage on the glass is consistent with sulphur from the fuel reacting with the glass. It is possible that by replacing the glass, it will alleviate this issue but if it doesn’t you will need to look at changing the fuel or fuel supplier.

What causes glass to blacken on a stove?

The glass may darken initially but will eventually clear under correct operation with the correct fuel. Wood that is not sufficiently dried and seasoned will always darken the glass.

The stove glass will self-clean when there is sufficient heat generated by the burning fuel i.e. when the unit is operated at the maximum air settings (i.e. Keep secondary air  damper above the fire door open). If a build-up of creosote occurs on the glass it may be due to low draft conditions, poor quality fuel or operating the stove at the minimum air settings for long periods of time. The glass should be cleaned when cool and cleaned with a non-abrasive cloth using warm soapy water. For stubborn deposits, a grade 0 steel wool can be used whilst taking care not to scratch the glass with any coal/ash deposits.

How should I clean the glass on my woodburner / gas fire or multi-fuel stove?

Answer : Wait until the appliance is cold, then using a damp cloth or kitchen roll, collect a small amount of ash from the stove and rub this on the glass. Use a new area of the cloth or new piece of kitchen roll and continue until all the stubborn stains have gone. Once you have done this, simply clean the glass with hob brite and it will bring it back to an amazing finish.

Contact us if you have an questions however we also advice contacting other organisations which might more specialised.

Useful Links


The official body recognised by the UK Government, HETAS is the national organisation working for consumer safety and the wider public interest in safe, efficient and environmentally responsible use of biomass and other solid fuels.

Solid Fuel Association
An advice centre funded by solid fuel producers and distributors and was established to encourage greater awareness of the benefits of domestic solid fuel heating among the general public.

Gas Safe Register- Ireland Gas Safe Register- Northern Ireland Gas Safe Register- Great Britain and the Isle of Man

Defra is the UK government department responsible for policy and regulations on the environment, food and rural affairs. Information on smoke control areas, authorised fuels and approved appliances can be found here.