Don't know anything about that heater but I can answer one general question. The heater uses what is called a millivolt system for power. If you look near the pilot light, usually right in the flame, there is a thermopile that looks like a cylinder with a wire coming out of it. Actually the wire may look like a skinny pipe. It generates a small voltage from the pilot heat to operate the gas valve and the thermostat system. If the pilot goes out or a breeze comes along or it isn't positioned right, no or low voltage. Your problem could also be one of the safety switches as you suggest. One of those switches could have a bad contact and the vibration of pulling off the panel could have tripped it. Check all connections are tight and you could try tapping on things. Best I can do.
Al