I have a Beacon/Morris BRU75 75,000 BTU Garage Heater. My heater don't ignite all the time. When it doesn't, the light flashes 2 times. So I unplug the heater and plug it in again, sometimes it fire up and sometime it doesn't. I cleaned the spark ignitor and the flame sensor. The spark ignitor works good. I was wondering, if it could be my gas valve? How do you know if it's bad or not? I taped on the gas valve when it was trying to ignite but notthing.