I have only had one problem with my draft door in the 6-7 years that I have had mine. Before I started burning mine all year, one year when I started it up the draft door stuck closed and blew the fuse, replaced it and no problems since.
I run mine at 180 also and it does not over heat with out power. Two years ago I replaced my water heater and had power off to the boiler for 2 days and the temp never got above 205, it just smoldered in the fire box.
I run a whole house generator when the power goes out so I still have lights and heat.
How tall is his stack, I am running 2 lengths of pipe, probably 12 feet with no problems.
I would see if they would replace the entire door instead of just parts. Maybe it is the temp sensor or controller, next time it sticks open have him shut off the power and see if the door closes, if it does it is not sticking but being held open electrically.
Last edited by af26yrs; March 16th, 2013 at 08:40 AM.