Where is the gasket located?
The door is most often sealed with a round gasket cord, which sits in a groove along the edge of the door, while the glass is fitted in a flat fibreglass gasket rope with tape so that it is not pressed directly against the metal. Fibreglass gasket rope is available in 8 x 3 and 10 x 3 mm and, for certain brands including Extraflame, Dal Zotto and Opera, in a version that fits their specific glass. On some models, the door is instead sealed with a silicone gasket shaped for that particular stove.
At the flue gas extractor motor, there is a flange gasket, selected by diameter and available under gasket for flue gas extractor motor. A used flange gasket can rarely be reused successfully, so expect to need a new one when the flue gas extractor has been removed anyway.
Cleaning hatches and other hatches on the stove are sealed with flat gaskets in felt or silicone. They are adapted to the individual brands and specified in length by width, e.g. 172 x 100 mm. The flue pipe joints have their own silicone gasket in Ø80.
Felt, silicone, rubber or cord
The material follows the stove's construction, so the new gasket must be of the same type as the old one. Felt gaskets are flat and compress when the hatch is tightened. Silicone gaskets are moulded and retain their elasticity, while rubber gaskets are used especially at the flange of the flue gas extractor motor. Gasket cord is available in a hard and a soft version. The soft version gives more when the door is closed, while the hard version retains its shape better. Measure the diameter of a section of the old cord that has not been compressed flat, or measure the width of the groove in the door.
The paper test reveals a leaking door
Whether the door gasket still seals can be tested with a piece of paper. Close the door on the paper while the stove is switched off and cold, and pull it gently. If it is held in place, the cord seals, but if it slides out without resistance, air enters at that exact point. Repeat the test in several places around the door, as the cord is often worn first at the corners and hinges. Soot along the edge of the glass is another sign, as smoke escapes where the gasket no longer seals tightly. Replace the cord along the entire length of the door so that the new one sits evenly all the way around, and glue it into the groove with heat-resistant silicone or ceramic adhesive.
