Hi Michael, I am not an expert and I will try to find out where the thermostat located and get back to you. I am may be able to upload some images of the unit for you as well. Hi Michael, I am not an expert and I will try to find out where the thermostat located and get back to you. I am may be able to upload some images of the unit for you as well.

It sounds like you combustion chamber temp switch has failed. It should heat up the combustion chamber then when it gets to a certain temperature, it should close and turn your fan on. It sounds like it's not closing and then the heater turns off on excessive heat high limit switch. Your going to have to locate the bad switch and replace it. Sorry it took so long to respond, I was out of the country It sounds like you combustion chamber temp switch has failed. It should heat up the combustion chamber then when it gets to a certain temperature, it should close and turn your fan on. It sounds like it's not closing and then the heater turns off on excessive heat high limit switch. Your going to have to locate the bad switch and replace it. Sorry it took so long to respond, I was out of the country