You will need to get the hydraulic leak fixed. You could manually run the other jacks up & down but if the leak is still present you will need to keep the reservoir filled to keep them operating.
Does the water get hot on gas mode?
The panel light comes on as a warning that the flame has gone out for whatever reason in the gas mode. Many times the older models would light up briefly and go out when the heater ignited. Usually here is an in-line fuse in the harness. What make and model is your monitor?
Mike, RVIA & RVSA Certified Master RV Technician
Amy, Dr. Assistant - Roxie & Mei Ling, four legs each
2000 Gulf Stream Scenic Cruiser 450 hp & 1330# torque
06 Saturn Vue, 06 Chevy Z71 4x4 & 2014 Corvette Z51 M7