When the gas valve clicks on, try lighting it manually. If it lites, then it maybe just needs a new igniter/flame sensor.
If all else fails, and you need to run it on gas, just hot wire 12v to the gas valve, manually lite it. If it won't lite, the gas valve is bad ??? If it lites, let it burn several hrs till stuff get very cold, then un hook 12v.
You don't need to burn at nite, just fire it once or twice during the day for several hrs.
Rich
'01 31' Rexall Vision, Generac 5.5k, 1000 watt Honda, PD 9245 conv, 300 watts Solar, 150 watt inv, 2 Cos 6v batts, ammeters, led voltmeters all over the place, KD/sat, 2 Oly Cat heaters w/ ox, and towing a 2012 Liberty, Lowe bass boat, or a Kawi Mule.