My Janitrol is about 11 or 12 years old. It will spark light the pilot and after a few seconds, the thermocouple is hot enough to call for gas and the burners light. Up to this point, it is normal. About every 2 years, I have a continual problem until serviced. The burners will light and then go out every few seconds to a minute and repeat the lighting process again. Every time I have repaired it by cleaning the pilot orifice located just below the pilot flame. The key indicator for being the same problem is that the spark ignition will spark several times to light the pilot just after the burners have come on and off, thinking that the pilot has gone out eventhough the pilot is still on. What happens to mine is that the burners cause the pilot to move slightly and the thermo-couple cools enough to make the circuit think that the pilot is out.