Baymak Combi Boiler Combustion Chamber Asbestos Board Type 1 – Duraboard Ceramic Fiber Insulation Plate

This is a Type 1 size duraboard ceramic fiber insulation plate used in the combustion chamber of Baymak combi boilers. This part, simply called asbestos in the field, keeps the heat of the burner flame inside the combustion chamber and limits heat transfer to the casing and surrounding parts. Plates produced today do not contain asbestos; they are ceramic fiber based.

It is shaped as a flat ring: a round opening in the center for the burner throat, a circular step on its surface and a single notch on its edge (as seen in the photos).

When Should the Asbestos Board Be Replaced?

• If the plate is cracked, broken at the edge or crumbles by hand.
• If it sheds pieces every time the combustion chamber cover is opened.
• If the plate has come out of place or become deformed during replacement of the burner, heat exchanger or cover gasket.

Size Comparison and Installation

• In Baymak combi boilers, combustion chamber plates are produced in different diameters depending on the model family. Before ordering, compare the outer diameter, center opening and notch position of the removed plate with the photos.
• The ceramic fiber plate is fragile; it should be kept flat when carrying and fitting, and not pressed at a single point.
• During replacement, old plate residues and soot in the combustion chamber should be cleaned out.
• The plate must not be forced into place; the notch and center opening must align with their seats.