Check the Ashpan

The ashpan seems like the simplest part of the stove, but a warped or holed one causes more trouble than people expect. Its job is to collect ash falling through the grate and, on many stoves, to control the primary air feeding the fire from below. If the pan doesn't seat properly, that air control stops working as intended.

Empty it regularly, but not obsessively. On a wood burner a shallow bed of ash actually helps insulate the firebed and improve the burn, so leave an inch or so. On multi-fuel stoves burning coal or smokeless, empty more often since those ashes are corrosive and will eat the pan and grate if left sitting.

Check the pan for burn-through, cracked handles, and a base that's buckled from heat. A handle that's about to fail is worth replacing before you're stuck lifting a pan of hot ash with the poker. Never empty ash into a plastic bin or cardboard box, and never leave it near anything combustible. Embers can stay live for well over a day.