I have been concentrating on converting the diesel Airtop 2000D models but with varying degrees of success. Jim Potter is still testing one on his van - it has been 3 months and appears to be fine. But... bench testing the conversion on various heaters gives better results on some heaters than on others and I can't find the happy medium that suits every one. So I am not satisfied with it totally. It is to do with the thickness of the burner pads mainly and I have to test various combinations in 1 or 2mm increments even a 5mm solid pad instead of a 1+1, 1+2, 2+1, 2+2 , 2+2+1, 1+2+2, 2+1+2mm etc. I can tailor each heaters pads to a size and configuration but would rather have a one size fits all for ease of servicing in the future.
Theoretically they are all the same but in practice they differ when used on petrol.
So it is still very much a work in progress and as its a strip down each time I change the pads it is rather time consuming! I may well have to just ignore those heaters that appear to be out of what would be the norm on conversion and leave them as diesel models but would rather get them all behaving exactly the same.
Hopefully by next winter I will be satisfied with them!
The more modern ST models don't seem to want to play ball at all on conversion at the moment and most S models are running at 85 - 90 degrees rather than the 95 - 105 degrees that is more preferable.