I had a nightmare trying to get my Lennox Pulse 21 furnace fixed when it would not start up. I was in bed recuperating from a heart attack and the furnace failed during a very cold spell during January 2002. The Lennox dealer that installed the unit (4 years previously) had to come to my house 7 times over a ten day period. They would get the furnace to run but it would quit and fail to restart. To my knowledge, I did not get the same service rep twice! Several parts were replaced including the thermostat (it was under a year old) The eventual trial and error fix was to replace two "Heatcraft" computers (part #9441 & 9512)which I am told failed simultaneouslly. The total repair cost exceeded $1,000 Canadian (about $600 US) I am disgusted with the quality of Lennox products and the ineptitude of their service staff. I paid top dollar for a quality high efficiency furnace and got ripped off! Fortunately we have a reliable gas fireplace that managed to keep the temperature in the house above freezing. I will never buy another Lennox product as long as I live and I will make sure that my friends, relatives, and neighbours are aware of the poor quality & service that Lennox provides.