One section of the 240 V power supply in the van has died, ie the power points beneath beds, including the one that water heater runs on, and under air conditioner. Rest of 240 V systems in van are OK, as is the 12V system. Have checked fuses in fuse box below fridge and all look ok. Is there another fuse somewhere, eg in the water heater, that could trip out just this section of the electrical supply?