Don't know your van model, but we had 2 weeks away in our new old MH before we found a) the electric switch for the hot water was deep inside the wardrobe and b) the gas water heater element was corroded beyond repair. I'm sure techy guys on this forum will tell you about fuses and such like.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.