Intermittent Startup Enviro Mini

My 5 year old Enviro Mini shuts down soon after starting. The #4 idiot light (2nd from top), lights. A reset, and it continues to shut down--sometimes without firing. Am I looking at a bad control board or bad high limit sensor?

Light # 4 on Heat output bar flashing means the 200 °F ( 93 °C) high limit temperature sensor
has tripped. The stove has overheated.
• Press the Reset button on the High Limit sensor and determine the cause.
Check the following:

• If stove is dirty, give it a complete cleaning.
• Convection Blower failure. or
• Circuit board control failure

My Napolean stove tripped its' overheat sensor last week. It turned out to be an intermittently functioning room convection fan. If I ran the stove above the medium heat setting it would consistently trip within a half hour. Since this fan picks up house air and blows it by the heat exchange pipes, it's common for its' squirrel cage blades to get completely filled up with dust. In my case the motor itself was also filled up with dust to the point the motor would stall sometimes. I'm a motor man by profession and have no qualms about running hot water through an induction motor (no brushes to foul up). I think this is less risky then complete disassembly that would have required removing the end plates that are held on by beefy metal tabs that I would have to bend. I did not submerge it but rather just put it under the tap with temperature high. Lotso crap came out. I then dried it thoroughly with a hair dryer. My motor has two oil hole passageways at both ends to allow oiling the bearings. I put half a dozen drops of 3m oil in each. I then wired up an AC cord to it an plugged it directly in the wall and let it run for a few minutes. This is the same way I tested it initially to determine it would stall intermittently BTW. After this procedure the shaft turned easily by hand whereas before you could feel a resistance. I can run the stove now on the highest setting - problem solved,

Good post on your Napoleon, I also recommend Marvel Mystery oil for the blowers. Good stuff!

Yeh, thanks Don.
Update - it stalled again. The shaft turned hard again. I removed the motor and put a bunch of alcohol down the oil filler points. Voila, stuff came out and the shaft turned freely! So either it was still dirty from the time before or I hypothesize I mounted the motor such that the oil filler tubes were south. Perhaps the oil I added left due to gravity. This time I mounted the motor with filler tubes pointing north. We'll see. The motor has quite a bit of end play but I've read shaded pole induction motors are ok with that. The magnetics will center the shaft in the middle of the end play by design. If I weren't so cheap I'd fork out the ~$120.00 for a new motor.....but I'm a fix rather than replace guy to a fault I have to admit.

Sounds good but check the auger bushing, you may need a new one.