Great piece of kit but will show the weaknesses in your plumbing. A few pointers--pick up a brass hozelock screw on connector for the water outlet on the heater as this is the bit that gets the hottest,it kept melting the plastic one that I recieved with it,2settings winter and summer if you have it on winter keep the gas set to low and on summer you can turn it up more,I just keep mine on winter with a low gas setting,takes a few minutes for it to heat the water so I usually start running the hose as I'm dragging it round the house go back for my poles and then it's half way there,wherever you mount it it is recommended that you heatproof that part, as the boiler does get hot,you can buy a roll of very thin heatproof insulation from b&q and I have done other parts of the van with it,next tip if your running a shurflo pump you need to adjust the back pressure as mine was causing problems-every time I turned water off at the pole it usually takes 30-40 seconds for the back pressure to engage the pump and stop it pumping,this is when you can spring leaks on your joints as your now running a hot pressurised system,there is a Allen bolt on top of the pump and if you wind this out it alters the back pressure and your pump cuts off quicker-felt obliged to write all this as can save a lot of stress as I had to learn the hard way,hope it helps
Graham