Hi paul, I agree with Dave, I would take the van round to your dealer asap, Sounds like you need a new replacement van,On my second service my Bailey Ranger series 5 year 2006 during their damp check showed up to 36% dampness on the nearside above the side bathroom area, upon investigation a slit was discovered in the rear panel, No sign of any dampness with in the van no smell , At the moment the van is at the dealers waiting to have a new rear panel fitted, believe it or not they are waiting a delivery of awning rails.
Please keep us all posted , makes you wonder what the statistics are per 1000 vans how many are failing.
Royston