mystery solved

[Catnapper]

For a couple years I have been using the same mask, same machine, same settings, same pressure and so on. Boring but effective. The water tank of the humidifier uses almost exactly half the water every night. Suddenly, about a week ago, I found the tank empty when I went to fill it. Odd, but maybe I forgot to fill it. Same thing happened the next few days, and I know I didn't forget all those days. I checked to see if the settings had changed but no. I needed to change the white filter and the nasal pillows. When I did that I discovered that both the filters had fallen out. I have been doing x-pap for over 11 years and never before had that happen.
Next morning, the water tank had only used half the water.
Who knew the filters made the machine use a different amount of water? What made them fall out?

Catnapper - Joanie

[Pugsy]

It's a known issue with the PR S1 models.
The filters aren't very secure and nothing much holding them in.
They've been known to fall out just from someone coughing and the back pressure blows them out or even a slight jostling of the machine.
If it happens too often then stretching a really skinny rubber band around the machine to include the filter is enough to prevent it from happening again.