Cracked Refractory Tile

[Jon mackay]

When the refractory tile in an oil furnace is cracked, is there anything that can be done to repair this or is replacement needed?

[Bob Harper]

There are replacement firebox refractory liners and materials commonly available from HVAC supply houses. You would need to check with the mfr. regarding what is approved for that unit. You would have more freedom to do what you want with an unlisted unit but then again, unlisted appliances should be replaced anyway. There are one piece molded shells, rolls of ceramic fiber, castable refractory cements and firebricks available. The firebox would need to be cleaned out and closely inspected to insure it is not damaged before a repair is undertaken. Very common to find furnace cement Band-Aids over cracks, which are not approved repairs.

Cracked flue tiles must be relined with a listed liner.