Help with Humidity on S9/H5i

I started using the ResMed S9 Autoset with the H5i humidifier a week ago. I am conming from a Respironics model (the generation before System One). I feel I have a humidification problem with the S9/H5i. I initially set it to Auto with 80F (I have a ClimateLine tube) and I would wake up with a dry nose and mouth in the morning and sometimes in the middle of the night. The water level almost never went down a significant amount. I then switched to manual controls. Humidity at level set at 5 and 78F for the hose. I still wake up with a dry mouth and nose although not as bad as when I was using it on Auto. I also noticed that the water level was not going down much. I checked the diagnostics every day and there was no mask leak.
So I thought maybe something was wrong with the H5i. So I borrowed my dad’s H5i unit for a few days and the results were pretty much the same as I described it above. BTW I live in Toronto, so it’s warm in the house but it’s also dry. Thus, I expect the H5i to produce more humidity to compensate for the dryness.

So I ask the following:
(a) Is my experience normal for the S9/H5i combination and the conditions I described above
(b) Could something be wrong with the S9 CPAP unit itself as opposed to the H5i humidifier unit?
My pressure varies between 7 and 12, the median being about 9.
Thanks

When you activate the warmup feature, does the metal plate at the bottom of the humidifier start to warm up? Does the orange light come on in the humidifier? If so, maybe try increasing the temp back to 80 and bump up the humidification to see if more water is used (and of course if it feels better).

If your humidifier is failing to heat up it may be difficult to determine whether the problem is a malfunction of the humidifier itself or a failure of the main unit to 'communicate' with the humidifier -- in 2012 I had a questionable humidifier on my S9 and because it was still under warranty I returned both parts of the machine and was issued a new blower and humidifier.

Hello
On manual settings I use almost a complete tank daily. 4 for humidifier and 60 degrees on hose.

Borrowing another H5i and getting the same results would tend to rule out failure of the heater itself. If you wanted to be sure the heater plate was receiving current from the CPAP, as the other poster suggested, from the humidity screen, press and hold the push-dial for three seconds to start the "warm up" feature. Carefully feel for heat on the bottom of your humidifier. If this is heating up, more than likely your problems are due to excessively high unintentional leakage coming out of your circuit.

In the studies done with the climate line they used 10 cm H2O that resulted in 35 liters per minute of total flow through the chamber. Regardless of all other variables, the system was able to output at least 85% relative humidity. What was not tested, and I do wonder why it was not, was the performance of the system with excessive leakage. Based on past experience, when leakage is high the heater plate stops heating and this creates a dried out patient with no water usage. When the leaks are on the low side, the patient results are the same but this time the heater plate gets more current trying to keep up with the extra airflow and lots of water is used. Rainout is likely in the second scenario.

(a) Though your experience isn't "normal", it unfortunately is quite common when large leaks (above 25 lpm unintentional) are present.
(b) I have yet to see a problem with an S9 that sent current to the heater plate when the "warm up" feature was activated.

Hope that helps. You might try going back to auto on the climate control and looking for mask leaks.

I set the humidity at 5 (more gives me rainout), and the temp at 78. That uses most of the tank, but it doesn't run dry. I still get a dry mouth, but am satisfied that the humidifier is doing its thing. I also have a cheap humidity gauge to see what the humidity is in the room.

Maybe turn the temp UP to wRm the water a bit? If I get below 70, the dryness is worse and I get a reindeer nose!