Submitted for consideration. Seems to me Daddy used to demand that we took some sort of a little tool and inserted it in a special place at the bottom of the wood/coal burning stove and operate it back and forth till the ashes fell out and that he cautioned us not to shake so hard that all the cinders fell out cause they retained enough heat to flare up and cause a fire when we hauled the ashes to the backyard and threw them out. The item shook was called a damper - not to be confused with the damper located in the stovepipe. DAMPER: A movable plate that regulates the draft of a stove, fireplace, or furnace. Cinder Any partly burned substance, not reduced to ashes.... See the 2nd paragraph under Mass Heater Internal Structure at the below url. http://www.cam.org/~pyromas/infoe.html This may be slow opening and in some instances will not load at all or completely but if you keep trying it will eventually work. It is so difficult to open that I have copied and paste the pertinent portion here: "Mass Heater Internal Structure To reach a sufficiently high temperature for the complete combustion of the wood load, at [ 600 C / 1112 F ] a strong fire is necessary. The firebox is filled with logs measuring less than 4 or 5 inches ( 101 -127 cm ) in diameter , because larger logs would burn too slowly. Air first travels from the primary source, via the admission damper found in the cinder box, then moves thru the the oven front, where one finds the wood feeding the combustion. The internal dimensions and the firebox inverted funnel shaped ceiling allows the heat to be reflected from the walls to the fire core, rising the temperature of combustion." Rsp. Jim Allen