I had my remstar pro model M series humidifier replaced because of that. They replaced because of the warranty. Last night the water level got very low and seems to be not working.

I have 2 units Respironics System 1 and Remstar Pro M series. I was using my M series and noticed this morning the water level got very low but still covered the metal plate inside the water chamber. I was testing both machines and noticed the plate never got warm during the test. Does anyone know i...