New Warwick Duo

Took delivery from SMC Newark on Thursday which was a thoroughly pleasant process and we felt very well looked after. The tow bar hadn't arrived in time so have got to return for fitting hopefully soon. Only had chance to play wendyhouse in Clumber Park for an afternoon and around 100 miles of motoring hence we have tested packing half the normal expedition kit in and the all important tea making & drinking ceremony. Big silly smiles on all counts but a couple of minors. I will be playing with the water pump pressure switch today as the pump runs continuously and the fridge needs attention. After 15 mins on gas the burner can be heard popping & sputtering which to my old engineer's ears means unstable combustion ie incorrect gas pressure or insufficient oxygen. Anyone had similar?