Hi, Thanks for info, yes i agree with you, what has made me aware is recently we have been getting the motorhome ready for trips away, Trume manual says that to get hot water, turn on electric switch (our is in the wardrobe) and then turn on switch on control panel with green light on, according to them this is the only way to heat the water on electric hook-up, so in the past this is what we had done and never realised the water was heating on it's own with just the water heater electric switch on.
As i said recently we hooked up the motorhome to our house 240 v hook up, we turned on the electric switch to test the water heater, then realised shortly afterwards the water was coming through the taps hot, but we had not turned on the water heater on the control panel.
Our concern is that Truma seems to contradict itself, if you only need electric switch to be turned on when hooked up, or turn on water heater switch with green light on control panel when on gas, unsure why they had not put this in their manual, this is why we became concerned when the water started heating with just the water heater electric switched on.
We had thought this is a problem which may have just appeared, and had hoped to find out if we have a genuine problem or it is just a characteristic with this setup, Thanks for your advice and hopefully you are correct and we will have nothing to worry about. Again thanks