They are fitted to the stove for insulation purposes, allowing your stove to burn efficiently but also acting as a heat barrier and preventing the flame from reaching the steel stove walls. They are a service item and will need replacing over time.
Cracks are caused by impact or vibration, often simply a log/solid fuel thrown in a little roughly or the door squeezed shut on an oversized log.
Crumbling on the edges or corners is a sign that the vermiculite is beginning to degrade and is ready to be replaced. How long it lasts will depend on how much the stove is used, under average seasonal evening usage this will usually be years.
Pinking; if the bricks change to a noticeable pink shade, this is a sign that the stove has been over-fired, or burnt at excessive temperatures for a prolonged period of time.
A hairline crack in the brick will not damage your stove. Replace the brick if;
- the hairline crack causes the brick to fall down
- you can see the steel body of the stove through the crack
- if you notice crumbling on the edges of the bricks, that exposes the steel
It is advisable not to light your stove if the steel is visible. If your throat plate brick has fallen down, don’t use your stove as it will distort the metal throat plate, that holds the throat plate brick in place.
We have a few tips on how you can make your bricks last longer:
- Do not use oversized logs in your stove.
- Cramming logs that are too big into your stove can cause damage to your stove, causing you to replace the firebricks more often
- Do not overfill your stove
- Ensure you only burn seasoned wood,
- Where possible, place the logs into the stove rather than throwing or dropping them. This reduces the shock absorbed by the firebricks, thus making them last longer
- If cleaning your stove internally do not use water or water-based cleaning agents, vermiculite will weaken if it absorbs moisture. Equally if you have drips coming down your chimney this can happen.