I have had my Resmed CPAP for about 3 years. It stopped working and I started receiving a Heating System Fault error message. I called ResMed and got a total runaround with their customer service and tech support. I called the supplier, Reliable Respiratory, and was told (when they elected to return my calls) that the machine was out of warranty and that I need to buy a new machine (surprise) for $500. Reliable Respiratory was always efficient when it wanted me to buy new supplies though. In the end I did speak to managers but $500 and a new machine remained the price for fixing this problem.
When I go online I see this is a "known" problem with the ResMed equipment. Planned obsolescence. What a scam!