Truma Error code 6

Have you checked online? There are loads of hits for the fault codes and you might find a wiring diagram.

a very quick Google found this ... (I'm sure there must be more) but it could be the fan motor is partially seized 🤷‍♂️ If you're lucky, it might be fixed with a squirt of lube. Could you put 12 volts directly across it to prove the actual motor?

Fans certainly not seized and this is on hook up so voltage should be good.
Unfortunatly the motor is inclusive of it's own Cct board so not easy to just put the supply across as it uses other inputs.
Gonna have to bite the bullet and take a chance on replacing the unit I suppose.

Update incase anybody else suffers this fault.

Spoke to Truma who confirmed it may be the combustion air motor as above but said I should take it to a dealer as it needed to be electrically checked to confirm. I asked them for a wiring diagram but they refused to send me one as I haven't been trained by them.
I carried out basic voltage checks and con checked the cable and it all looked good to me so I got a used unit of e-bay for £85. (they seem to be between £250-300 new)
Fitted it (3 torx screws and a plug) and happy days we have heating again!!!!!!!!
Whoop, whoop, thanks for nothing Truma!!!!

Well done, I wish I was as clever I had to have a new circuit board on my Truma system, it failed at less than a year old and fortunately was replaced under warranty. Had you thought about having the defunct one serviced to keep as a spare?

David

There's a company that overhauls them for £95.
Might be advisable as having on in salt wouldn't be a bad idea

Remember the days when folks would give you the benefit of the doubt and accept that if you were asking technical questions you might just be a bit handy and clever enough to fix stuff? Now they block you at every turn and manufacture without any thought that somebody, some day might want to fix it rather than just add to landfill.

Elf and Safety dear boy and,,just in case of "litigation "when you take them to court afterward for wrong information

Last year I had to have a new heating element kit for my Truma. Although only one element had failed I had to have the kit of two at over £300 plus fitting so best part of £600 in total. Talking to my caravan service guy recently he told me that Truma are going to / have stopped supplying the kits on the basis that service engineers haven't got the skill to fit them. Instead they are only supplying the complete boiler unit at about £1000 !!! (plus fitting of course). My faith in Truma as a usually helpful company is starting to wain a bit.

I think it’s more fundamentally stupid than that. Take the current Ducato, there is an oil level sensor inside the engine. Presumably because Fiat think we’re all too lazy to use the dip stick? Fair enough, but a lot of them fail. You can ignore it, but a generic warning light becomes a permanent feature on your dash which may frighten off any future purchaser. Replacing it will set you back about a £thousand, mostly labour and VAT. 

I purchased a BMW privately many years back. It was from the generation of cars launched in the early 1980s with on board computers and electronic this & that. Having been reared on Ford Cortinas and the like, I assumed the faulty offside indicator was a £5 blown bulb or flasher unit. Wrong! It was a small component on a PCB that cost £750 to replace, which was exactly what I’d paid for the car! Probably made assembling it quick and simple, but just a future headache for the hapless folks who purchased them.