- Baxi Burnall 18" Ash Pan - Replacement Baxi Ashpan to fit Baxi 18" Burnall Fires - 18" W355MM X H210MM X (TAPER 250MM) DEPTH 210MM - Suits 18", 20", 22" and 24" fire openings PLEASE NOTE 18" REFERS TO THE WIDTH OF THE FIRE OPENING NOT THE SIZE OF THE ASHPAN.