Wood burning stoves are a source of winter warmth for millions of Americans. They provide heat by burning a plentiful, relatively inexpensive fuel, and they add winter charm to almost any home. The addition of catalytic combustors makes a huge positive impact on stove efficiency, and they also greatly benefit the environment. However, combustors do require periodic attention to keep them functioning as intended and to ensure a long lifespan. Here are some maintenance tasks that you need to keep in mind:
How a catalytic combustor works
A basic overview of how catalytic combustors work will help you become a better user and understand why it is important they be maintained. A catalytic combustor consists of a grid structure, usually made of steel, porcelain or another appropriate heat-resistant material, that is coated with a platinum or palladium catalyst. The combustor rests inside of the stove's exhaust flow.
As hot gases from the stove rise through the combustor's grid, the metal catalyst causes the unburned fuels to undergo a secondary ignition and burning. This burning results in much purer stove emissions that consist mostly of carbon dioxide and water vapor.
How to maintain your catalytic combustor
Your catalytic combustor generally doesn't need much attention during the course of the winter months. However, you should remove it for inspection and maintenance after you have lit your last fire for the year. Here is what you need to do:
Tools and materials needed
- Cotton work gloves
- Face mask
- Clean 2-inch paint brush
- Mineral oil
- Clean cloth or rag
- Cotton swabs
1. Wear cotton work gloves and a face mask while performing work on your stove - the soot and creosote can be difficult to remove from your hands, and you don't want to inhale the fine ashy particles.
2. Remove the catalytic combustor from the stove – most combustors are easy to remove, but be sure to follow your stove manufacturer's instructions for details.
3. Carefully inspect your combustor – gently wipe away the loose particles of soot and ash on your combustor using the clean paint brush. Keep a firm hold on the combustor; ceramic grids can break if it is dropped, and the catalyst material can chip and break, as well.
4. Remove grid obstructions - if you see any obstructions in the grid openings, try to remove them with your paint brush or a cotton swab. Do not poke at objects with a screwdriver or other hard objects, or you risk damaging the catalyst.
5. Clean creosote accumulations – creosote accumulations inhibit your combustor, and they can also be a source of dangerous chimney fires. The presence of creosote can be due to the following:
- Burning wet or dirty wood – never burn anything in your stove but clean, dry firewood. Wet wood or wood containing debris will cause your stove to burn "dirty", and creosote byproducts will coat your combustor.
- Insufficient heat generation – catalytic combustors require that exhaust gases reach temperatures of 500 degrees Fahrenheit to function. Check your stove's flue to be sure it is properly set for maximum burning efficiency.
- Worn catalyst – creosote will start accumulating if the catalytic reaction isn't sufficient to burn all of the outgoing gases. Most combustors can last around six years, if properly maintained.
Creosote is difficult to completely remove, but you may be able to clean a portion of it using mineral oil. Gently apply it to the catalyst with a clean cloth; don't scrub too hard, or you may wear off the coating. Any mineral oil residue will evaporate within a few minutes. Any remaining creosote will eventually burn away as long as you are able to achieve a consistently hot-burning fire.
6. Reinstall your combustor – some combustors use gaskets to hold them in-place, so be sure to install a new gasket if applicable. Your stove or combustor manual will contain information on how to change gaskets.
7. Check your combustor for proper functioning – after you have cleaned your combustor, you will want to check it for proper functioning. Build a hot fire using clean, dry wood, and check the smoke coming from the chimney. If your combustor is working properly, the smoke should be wispy and white; this is a sign that it is producing water vapor as intended. Black or gray smoke indicates the combustor isn't working properly, and it may be time for a replacement if you have cleaned it and checked for proper flue settings.
If you need more information or assistance with keeping your combustor and chimney clean, call a local chimney repair company, like A1 Everlast Construction.