Hello, I am brand new to the caravan scene and have just bought my first recently, I have noticed in the fuse cupboard that the heater light is stuck on, the van has no heater just a gas fire, so I can only presume this is the water heater, however the caravan is not hooked up to electric and the battery has gone flat really quick, there is no water in the heater and the gas isn't connected so I am stumped to why this light is on, can anyone help please