BTW, updated my profile with my equipment. I did not put the software because I am not sure which I have. The 5 is still lit dim, but the heat plate is getting hot. Maybe the led is just losing brightness.

Okay, after reading up on some things today, I tested the heating plate and it is getting hot, even on 5. I learned about the System one and Classic, it was on System One humidification. I will change to Classic. Either its not heating sometime and heating other times or the System One Humidificatio...

Thanks guys. I may take the humidifier apart just to make sure nothing came loose. I take it on motorcycle trips and it gets bumped around some.

I am not home right now, but I am pretty sure it is the 50 series. It has the white faceplate and side panel.

I have had a Phillips System One CPAP machine for several years now. I have always had the level at 5 for the humidifier. I noticed last month that the unit would not work on 5. I also noticed that the 5 that lights up on the unit was dimmer than any other setting. I lowered it to 4 and it worked fo...