I have a 96 Itasca Suncruiser 37w. I had the rv for a short time and never had to turn the heat on until now. I can't get the heat to come on. I don't know if I am doing something wrong. The furnace definately works because the water heats up, the frig works in LP mode and it is also evindent that it works by that blue flame that i see when I look at the furnace. When I turn the thermastat to the heat setting, the blower turns on but I get know heat. Is there some switch or magic button I need to push? I am lost and cold, can anyone help me? Thanx.