I agree that you should have a spare. I happily store the next cat just like I do the next roll of toilet paper. You don’t want to run out!Quick question for all you BK folks. Being a belt and suspenders kind of guy, I'm thinking it might not be a bad idea to have a spare combustor in reserve. Problem is I can't seem to find anything when I do a web search on the part numbers (Combustor part number: 115-0336A-M or 115-0556) supplied in the user manual. Anyone know what I should be ordering, and where?