Info on water heater. On my 04 236S the two switches with a red light between them are as follows. The left hand switch is for 110v electric & the rt. hand switch is for gas.
I think that 04 was the first year they installed the gas/electric as standard equipment.
I had leakage at the pop-off when I used the heater on elect. After checking the temp of the hot water & finding it well below the pop-off valve setting, took it back to the dealer & they installed a new pop-off valve which cured the problem.
Hope this helps.