I am afraid I can't answer the question yet but mine does the same. It does usually switch to electric after a while but then goes back to gas from time to time, usually at peak times when other campers switch on appliances and the voltage fluctuates. I had it checked by a caravan service engineer yesterday but he could not explain the problem. It is still covered by a warranty so I will keep trying to find a solution and let you know if I find any more out.
Richard Kirby, June 2009