I have a kroll waste oil burner in the corner of my garage it's amazing and burns clean as a whistle only a little smoke from chimney on initial start up then nothing at all and chucks out loads of heat and since iam a garage I've loads of oil, saying that I ran out on Friday so had to go to my mates garage and get a couple of 45s. It's a little bit mucky to clean the oil pan on a morning but well worth it we even have a frying pan which we can sit on the top plate to cook our bacon in.