....so got my van back this afternoon the hydroheat is working great now.

apparently it was something to do with the return pipe not going to the bottom of the tank.ford says they sometimes dont bother....and mine just happened to not have it!

.not many people with these vans tap into the fuel tank to run a diesel heater!
grippatank though have been fantastic from start to finish.great customer service .its been a ballache for them though as i live so far away from their fitting centre.
i think every time they fit a heater now theyll make sure they run fine with the engine off for longer than 5 mins.

a very professional and friendly company and i wouldnt hesitate to recommend them if you plan on getting a system fitted.