I hope this is an appropriate group. My dad used to have a heater in his workshop that was fuelled by waste oil. A rather noisy contraption IIRC but not smelly and it certainly warmed the place.
He's now long gone and so is the heater but is such a thing still available? I seem to recall being told that these were no longer available.
For reasons unknown I am now responsible for oil changes in all family, and some extended family, members cars. Waste oil is kept in a 1000L ibc container. Makes a stink when emptied down the drain in the road!! No, I don't really do that. I use Malory Environmental who empty the ibc as required. The cost of doing so is about £10/100l
As I now have my own workshop (non-commercial) which is chilly in winter it might make some sense to make use of waste resources.
Thanks