We had the AM30 model. It ran well for a few years and then became unreliable. Numerous parts were replaced at considerable cost. Eventually the main water tank leaked into the combustion chamber. The leak took a long time and many service visits to diagnose. Via the service company, Lennox decided to replace the dead AM30 with their redesigned AM61. That was supposed to be the new generation and solve the problems of the first generation AH30. Tht unit was installed in 10 - 2003 and it too has been unreliable. It is increasingly unreliable and we have now lost confidence in it. Our service company that has much experience with Lennox says they don't know how to make the system run reliably even after technical consultations with engineers from Lennox. We are in expensive and uncomfortable trouble. There is no apparent reason to trust the system at this pont.
Fortunately, none of our pipes have frozen - yet. I'm trying to recover from bronchitis and sinus infection and the major fluctuation in temperature inside are probably not helping me recover.
I hope Lennox comes through with equipment and labor for a replacement system. Our service company owner says Lennox has a good reputation for standing behind their products. We need Lennox to come through for us and for their own reputation.