Ok, so replacing the ignitor was actually very easy. All I had to do was disconnect the gas manifold from the burner assembly, two nuts, and swing it out of the way, remove I think 8 screws holding in the burner assembly which were rusty but with some penetrating oil, they all came out no prob. Then just slide the burner tray out. The burners had some crud on the vents which I cleaned off with a wire brush. The ignitor was mounted on the back of one of the burners. Yes, one of the wires was broken. No rubber grommets on the sheet metal where the wires go through. Emptied out as much rust/crud from inside each burner, slid the assembly back in, swung the manifold back into place (have to check that the gas connection isn't leaking) and replaced the rusty screws with new ones. I also removed all the gas nozzles and cleaned out the cob webs. Anyway, I still have a problem. I replaced the ignitor as well as the flame sensor and still its not firing up. It cycles 3 times, fan seems to be functioning properly, I can smell gas so I know the gas valve is opening however, the ignitor isn't getting hot at all. I even disconnected the new ignitor and connected the old one outside the heater, after I was sure the gas dissipated (I did reconnect the broken wire and check for continuity) and the old one didn't get hot either. So I'm not getting any voltage to the ignitor. The Fenwal Ignition Control Module PN R0386800 is giving me an "Ignition Lockout" indication after the unit tries to start 3 times. As far as I can tell there hasn't been any ignition at all.
Any ideas? I know its not recommended, but can I fire this heater up with an open flame? Maybe one of those long grill lighters? Wife is pressuring me to get the pool heated up and I'm sure she would be ok with me potentially blowing myself up.