We have a E.K. Industries model TK28MM it was tested by P.F.S in Madison Wisconsin on 3-1-80. It says tested with UL standards UL1482,UL727,UL737. The previous homeonwer installed it and hardly used it judging by how new the chimney locks and how the furnace looks. Anyone now if they are still making them or under a different name? Maybe someone else has one it is the best thing since sliced bread and will never need replacing. Any info on this unit would be appreciated.