ResMed S9 AutoSet humidifier question

I have been using my ResMed S9 AutoSet for 3 nights now. I use it for approximately 7.7 hours each night. On the first night I filled up the humidifier reservoir with distilled water. The moisture level was set on 2. The next morning I went to dump it out (as instructed by the DME) and noticed that the water level hadn't gone down. Not one to waste, I decided to leave the water in the reservoir but set the reservoir next to the machine because DME also told me that it is bad for the machine to leave water sitting in it all day. Also, I noticed that the water and the heat plate on the reservoir was ice cold but didn't give it much thought. The next morning I noticed that once again the water level hadn't gone down but maybe a tiny bit and again the heat plate was ice cold. So I called the DME after hours number and they had someone call me back. She had me turn the moisture level up to 6 and run the machine for about 2 minutes. The heat plate in the bottom of the humidifier was slightly warm so she said it must be working and maybe I just needed to turn the moisture level up to 3. So last night I did. This morning, water level hadn't changed and once again heat plates were ice cold.

So is my humidifier actually working? This is a brand new machine, I just got it on Thursday and have only used it the 3 nights.

Also, the DME told me that the temperature setting (which is 80 degrees) is for the climate control hose and has nothing to do with the humidifier temperature. Is that true?

The 80 degrees is for the air in the climateline hose temperature and has nothing to do with humidity.
The settings 1 through 6 is what controls the humidity that is delivered...
When a person has these 2 choices then their Climateline hose is set to manual..as opposed to automatic.

You live in Oregon? By chance has the relative humidity been very high there? I know in the northwest along the west side of the mountains humidity is often on the high side due to lots of rain.
The settings 1 through 6 involve an ambient humidity sensor and if your general ambient air humidity is already very high then the machine won't do much heating of the water to increase humidity output and thus is won't use much water.
Settings of 2 or 3 are already for relatively lower humidity delivery. It's possible that your ambient room humidity is already pretty close to what 2 or 3 setting would deliver so there just isn't much need to warm the water to increase humidity output.

So I suspect your minimal water use is just from the fact that your settings along with ambient room humidity mean that there just isn't much need to add a lot more water to the air in the hose. If you lived in the desert then you would see the water being used up more.
I have mine set to maximum level of delivery and when it rains it doesn't use any water to speak of but other times it might use 1/2 to 3/4 of the tank.

Thank you Pugsy! That probably explains it. I just thought between the lack of water use and the ice cold plates that maybe the humidifier wasn't working at all.

If it warmed up quickly when you set it to 6...it's working. It never gets really hot like people might think anyway..just warm.

i have the same problem... frustrating!