Hi All, I have not been here for a while, but I learned something important last night. I have a seven year old Respironics M-Series Auto, but I expect this will be useful for any older M Series machine. The quality of my therapy has been going down fast, even though the machine seems to be working ...

I have something you should try. I have an M series also, about seven years/20k hours on it, and lately the quality of therapy has been dismal. In my case, the coarse filters are washed at least monthly, the fine filters changed as often. I have never run it without both of those filters in place. M...