Our 251 RKS has a tank monitor panel with water heater (gas) and water pump switches in the bathroom. Between the two switches is a GFI light. When the water heater (gas) switch is turned on the GFI light will burn for a short period. I have not seen anything negative happening. I have ignored the situation. Need I take this seriously?
andy10, your system is working correctly. The GFI light is the DSI light for the water heater. Evidently you didn't get a manual or you have not read it. Google for RV water heater manual and all will be explained.
If it's anything like our water heater light, the light will light for a few seconds while the water heater is turning on. It will go out when the water heater lights. If it stays on, there is something wrong and the heater is malfunctioning or we forgot to turn on the propane.