I recently had a problem with my Carver Fanmaster, it worked fine on gas but there was no heat when switched to electric heating. Then co-incidentally I happened to read a letter in the Caravan Club mag (August page 29) about the thermal trip. Finding the trip was difficult but with the help of the website mentioned in the letter (go direct to --- http://www.stowford.co.uk/faultfinder/carver/fanmaster.asp) I reset the trip and all worked perfectly!
To get at the trip you need to have access to the rear left hand side of the heater. On the side of the terminal box you will find a flexible flap which when pushed in resets the trip. In my case I have been able to cut a whole in an internal partition which will allow much easier access in the future. A WORD OF WARNING - ISOLATE FROM THE MAINS BEFORE INVESTIGATING!
To get at the trip you need to have access to the rear left hand side of the heater. On the side of the terminal box you will find a flexible flap which when pushed in resets the trip. In my case I have been able to cut a whole in an internal partition which will allow much easier access in the future. A WORD OF WARNING - ISOLATE FROM THE MAINS BEFORE INVESTIGATING!