after lighting the heater, when i put bottom cover plate back on pilot light goes out. also if i turn to off position it goes out. When i light it and move to any position(lo, med, hi) it stays on just fine what do i do?
Examine the gas pressure supply, the regulator supply to the burner, and check the pilot orifice for obstructions. The flame might be a bit small or have strayed from the thermal sensor due to pressure or dirt.