Catalytic stoves burn very cleanly and efficiently at low to medium heat outputs as stated before. The thermal stress of burning particulates and volatiles, is concentrated in the catalyst, which is a durable ceramic material built to withstand normal temperatures up to 1,700 degrees. Focusing all of the high temperatures activity in the catalytic combustor allows other stove components to stay in comfortable operating temperatures and not get over heated.
The catalyst should be replaced every 12-14,000 hours. Let's say you burn your stove from November through April (5 months X 30 days X 24 hours/day 4 years = 14,000 hours). If you use your stove less than 5 months a year or as intermittent or back-up heat, the replacement cycle would be proportionately longer.
The ACI Firecat catalytic combustor is backed with a 6 year pro-rated warranty. Read about it in my next posting.