Fan in Thetford gas oven

The fan in the oven, as I understand it, is only to disperse heat when it gets to a certain temperature and is not part of a 'fan oven' as we would understand it on an oven at home. The fan on ours cuts in and out periodically so it would seem that yours is working OK. 

The oven in my previously owned Buccaneer Caravel, also a Thetford, had the fan fail which was noticed whilst cooking the bird (crown) for Christmas dinner. As noted above, it’s a air circulation fan which is bi-metallic switch controlled to prevent the surrounding cabinetry from overheating during prolonged use of the oven. It was only due to the faint smell of scorching wood I noticed the problem, the woodwork around the oven being very hot to the touch.

The fan is mounted on the top of the oven and is very easy to replace. Replacement fans can be purchased for less than £3 from RS Components. Half a dozen or so screws to remove then slide the oven out of its aperture, just enough to access the fan but not so far you need to disconnect the gas supply. I supported the weight of the oven on the caravan step. Cut the two cables and remove the screws to take the fan out. New fan in and using heat shrink coated crimp connectors, reconnect the cables. Replaced the oven then tested, all working again. Took around half an hour.

The fan is a Sunon DC Axial Fan, 80 x 80 x 25mm, 41cfm, 1.7W, 12 V dc 

A squirt of WD40 never does any harm and generally  cures most sticking components. 

Be sure to mop up any excess with kitchen towel though.

Many thanks for responses. Will get OH to read and decide course of action. WD40 gets used often here.