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We have an M1A1 with a heater problem. The heater runs for a while and then shuts off. In thought maybe a fuel pump???? Seems their may be an adjustment on the flame detector switch???? We use this tank a lot for towing and it's been snowing so a heater would be nice Thanks!

"Weed",
I'm not trying to be insulting but is the left front fuel cell full??? If it is then it could be the thermostat. I'm assuming it's a Stewart-Warner. The thermostat is the shiny metal oval about 4 inches long and 2 inches wide with a small set screw coated in red lock-tight. A quick check is to by pass it by putting both wires on the same post, Should be attached with 5/16" nuts. If it starts and continues to run then you've solved the problem. Just don't run the heater on high since it keeps it from burning up and causing a fire. Just replace the thermostat from another tank. That's assuming the heater actually went into start cycle and put heat out. Sometimes the igniter will actually get warm enough to trip the flame detector switch to on without an actual burn. In that case adjust the Flame Detector Switch. That's done with the heater off but power on. The set screw is adjusted with a small flat tip screwdriver. The screw is on the side also covered with a little dab of red lock tight. Turn it clock wise until the fan kicks on, then back it off until it stops. Then turn it halfway back but not far enough to kick the fan on again. All these things can be done with the heater in the tank. If you have the same problem then it's the wick leading to the burn bowl. Now it need's to be pulled and either the heater replaced or the burn bowel in it. A quick one time fix is to shove a cigarrette butt down the well of the ignitor tamping it in with a pencil, sometimes you get lucky and it will act as a wick to the burn bowel and last for a few starts.

All instructions stated above are given as suggestions to fix a Stewart Warner Heater but are in no way intended to by pass authorized maintenance procedures conducted by qualified personnel, any potential damage or injury sustained is solely the responsibility of the person who choses to disregard established maintenance procedures

Good Luck "Weed"

Joe D
Joe D

Thanks Joe! I'll give it a try. It does start and put out heat but it quits after about a minute or two. It'as been snowing and we could use the heat

Joe,

I got the heater working today. Here's what I found: I had all of the airflow to the turret shut off. I was hoping to put it all into the driver's compartment where I was at. Anyway, appears this caused some back pressure and (I guess) caused the heater to overheat and shut down. I opened the airflow to the turret and it works fine now.