I refilled my reservoir today. It was low and apparently the cause of my problem. It was a little less accessible than I thought it might be from photos. I used a turkey baster but pushed some tubing (fish tank tubing) into the end to be able to just fill directly. I pulled the bulb off the end of the baster and just poured carefully into the open end with the tube inserted into the reservoir. That worked great without any spills. When I got to the desired fill level I pinched the tube and pulled it out. I cycled it once, let it set to allow drain back and then refilled the reservoir to the mid point just to make sure I didn't overfill.