A vacuum cleaner may be used, but never use high pressured air to blow the cells free of any build-up. This can damage the cell walls.
Any cell blockage can be removed with the use of a pipe cleaner or a cotton swab.
Should the combustor’s cells become masked with fly-ash,...use a paintbrush or soft-bristled brush and dust the combustor gently.
Never use anything abrasive to clean the combustor.
Normally the catalytic combustor requires little or no maintenance because it generates such high temperatures, it is basically self-cleaning.
However, should the combustor become masked with soot or creosote, it is possible to burn the accumulation off by opening the bypass and building a hot fire.
Once the hot fire is created, close the bypass halfway and burn for 30 to 60 minutes with the bypass left in this position.
Never use cleaning solvents to clean it.
It would be wise to check and clean the combustor, if necessary, before each burning season and inspect the flue system for any signs of creosote build up.
A clean flue helps prevent chimney flue fires.