Tried posting this on the RV Appliances section with little response. Hopefully I will get some good info here.
Been trying to troubleshoot both of my Atwood 8500 series furnaces as both have given me the lockout codes (3 quickly flashing lights followed by a pause) and the next step is getting to the electrodes and gas burner assemblies sitting behind the gas valve to check them out.
One problem: the outside draft cap assembly (aka exhaust tube)which sits inside of another tube at the back of the gas valve is proving to be a SOB to remove. I suspect rust has set in place. The one wing nut has been removed and I have tried PB Blaster over several days and a lot of wiggling and waggling with no luck, along with a fair amount of brute force and gently tapping at the join with a long screw driver.
Heat may help, but I cannot get heat that far back in the area without torching some wires and rubber grommets along the side.
Anyone else had this problem and what did it take to remove the draft cap assembly?
Thanks for any usefull tips, as usual
ps, it will not help to remove the furnace from the MH as the area I need to access is completely enclosed by sheet metal.