It makes a difference I always use premium diesel in the van hence also the heater.
It would be interesting to find out if he is using 'gas oil' and which brand he is using if he is.
The canal boats had lots of problems with Webasto (and all the others) sooting up with carbon around 12 years ago. Webasto ran tests and concluded the same diesel heater run on road diesel didn't soot up like it did run on red diesel supplied by the inland marinas.
Since then the quality of diesel has improved due to regulation. However, the last time I heard, lower quality red diesel was still available for sale on coastal marinas because these boats would be out at sea.
There is a Youtube video of a farmer cleaning the carbon out of his Thermo90 on his tractor. He appears to be quite skilled at it. I did wonder if this was something he did regularly and if so, was it fuel related?
A local Jet service station close to us is now selling gas oil. I have asked myself the question if I should contemplate adding a second tank for my heater.
