Yesterday, with the rain finally stopped I got into the 'oily bits' to see if there was anything simple wrong with our Travel Power unit. After carrying out the tests recommended in the instruction sheet it seems like the stator windings have failed. I then tried to get some sense out of Dometic, the company which makes it. I did find them hard to deal with at first. After a lot of button pushing (another on of those multiple choice automated systems) I finally got to the right department who gave me numbers for two local dealers. The first said "What's Travel Power?" which gives one a lot of confidence. The second wasn't answering his phone. After trying all day, and half of this morning I got back to Domitec and made a nuisance of myself until they chased up someone who would help. Finally I found a company who will provide a complete service exchange unit, but not until next Monday. At least it will be the genuine article, complete with guarantee.
It looks like we'll be here in Chester a lot longer than we had planned, but I can think of worse places to be stuck.