I’ve had my Resmed for some time. It’s making noises which I’ve looked at resources to address, as well as taking it in for replacement parts. What concerns me and what I haven’t noticed before is the heating of the water in the reservoir unit. It gets hot on the bottom & water warm after adding fresh , which I do at least twice nightly. I’m concerned for my lungs. I don’t recall this being an issue before. I have a heated hose. I have obstructive issues leading to apnea. Untreated apnea led to AFIB, a pacemaker. My apnea is under control. Temp 78 , pressure relief on, humidity 5, climate control manual, smart start off, ramp time 20, set 12-14, but doctor hasn’t called me back to verify if the 12-14 setting was setting before it went in for repairs. Suggestions? Is the water supposed to heat up?