Koker 160 with Direct Vent Hopper fire

How do you know if the fume switch trips? when I had my hopper fire I thought it was because of my own tinkering to try and save coal but I am wondering if it was due to this as well. Mine happened when we had 2 consecutive 60 degree days and perhaps I didn't have enough draft at the time. When I found it I immediately unplugged it and emptied the hopper and due to my inexperience didn't look into the reason it happened as much as I should have.

Vulcan, I believe in a Koker with Direct Vent a hopper fire is caused by TOO much draft not TOO LITTLE draft.

vulcan,
The fume switch automatically opens when you lose the draft. When it does, it should shut down all the motors: stoker, combustion and vent. The furnace then goes cold. Once the draft problem is solved, the switch can be reset by depressing the red button in the center and the furnace restarted.
The problem we've been hearing about is the Koker's wiring is such that the vent motor has been left to run while shutting the other motors down. This draws air thru the coal in the hopper. The fire follows the air path up into the hopper, melting the nylon cam along the way.

CoaLen,
Thanks for the info when I had a hopper fire my direct vent was still running but honestly not sure about the other motors i went to check on it after getting home at 3 am after my 10 hour shift and wasn't thinking as I should have been, as soon as I saw it I unplugged it without checking to see what was still running. Nylon cam and screws were melted by this time and the worst part to replace was getting the old melted nylon off the pusher. Since I didn't have to reset fume switch I guess mine didn't trip.

Inside the electric box there are two black wires coming from the direct vent. One should be connected to 2 white wires. The other should be connected with 2orange and a black(from combustion fan). Mine came from the factory with one black connected to 2whites and the other black connected to 2YELLOW. Hope this helps!

Thanks shanedoe.
That information should be exactly what we need to check our Kokers.
-Len

It looks like mine came from the factory wired incorrectly as well I have one of the black wires from dv connected to 2 yellow wires and the other is connected to 3 white wires. I am going to consult with keystoker and possibly the dealer before I make any changes to the unit. My koker was purchased new in April 2012 I am curious how long this was going on.