Another alternative and I did this on my waste oil boiler, make your own silicone rope gasket.
Get yourself some one inch rope gasket and some high heat silicone. I just pick up a caulk tube of Permatex red.
Place a bead of silicone in the door channel after you clean it. To get a superior gasket work as much silicone into the rope as possible, place a glob in one hand then work it into the rope, keep repeating until the rope has as much silicone as possible in it. Place into the door channel, then squeeze more silicone onto the rope and use a putty knife to work smooth. Place waxed paper over the silicone then close the door lightly to leave a small impression. Prop door open for at least 24 hours to dry, 48 is preferable.
DO NOT wear the silly latex mechanics gloves, to get the best possible seal you must become one with the silicone….