When I was in colorado from 2000 to 2002 in the denver area, I remember working on these lennox gas fired funaces I believe was called the pulse. Everyone dis-liked these units. they fired with a spark plug like from a car, had a flapper on the intake that often needed changed, and the units when running were very noisy! Just curious if anyone has worked on these and your opinion. Thank God I only had to work on a few!