H4i humidifier - what does blinking mean?

When I turn on the humidifier, the light blinks/pulses slowly (kind of obnoxious while trying to sleep) for a while and then goes dim after a while. I tend to have the humidifier set to 1.5-2 out of 6 based on the DME's suggestion. What does this blinking mean? The manual seems to indicate it should be solid while heating and off when done heating.

I've never seen the plate get warm except when I put it on the top settings. I'm also not clear where I should put the dial, maybe 1.5-2 is too low so it doesn't bother warming the water. I live in the mojave desert, and the relative humidity is routinely 5%... Occasionally I've seen it around 14%, so its pretty dry. I never use much water, which I find surprising considering how dry it is out here!

Link to H4i user manual:

http://www.resmed.com/in/assets/documen ... ow_eng.pdf

The light responds to the sporadic heating cycle designed to help prevent overheating. The pulsing is normal.