I have a 1984 Jayco Cardinal the heater does not have an igniter (should it have a igniter, I have to remove the little door with the little round window to light the pilot.) The second to last time I used it the fan would come on but the burner would not light I changed the thermo coupler but it did the same thing. Some times it would light some times it would not. A friend said some times if the LP tank is low that happens. The last time I used it the same thing happened I also ran out of gas in the tank I was using and switched over to the other tank and it worked for the rest of the night. What do you think.