If ya didn't check yet I would definitely heed Fmattox73's question. I had a Coleman Niagara that had a thermostat with a needle you could move to change the temperature setting, but underneath the thermostat was a on/off switch and it was very hard to move the switch. The thermostat itself was mounted very low and close to the floor so it was difficult to even see the switch. Take a look if you haven't already.
Marty, Jenice and DD