Hi, our van is a Chausson and has a Combi E - you have the choice on electric only mode to select 900W or 1800W on the secondary electric switch. Then use the other switch which is the standard one if you don't have the electric. Turn it down once from the central off which gives blown air heating and some hot water and down again to give heating and 60 degree water. I have found the water to be very hot on the 1st setting. If you want hot water only you turn the standard switch up once for 40 degrees and twice for 60 degrees. Thank God for the internet and kind people posting instructional video clips - I would have (maybe) worked it out myself - it doesn't appear in any of the Truma users manuals I have looked at so far. We are hooked up fairly regularly and don't see the point of using our gas when we've paid for the leccy with our pitch fee. Bob.