I've used the AWS in my 3 boxes for several years, replacing the regulator off and on. This year the regulator seems fine but there is no water coming from the sensors (all 3). Last winter I bought a new sensor from EB because I was going to add a box but I didn't. I took out the old sensor & tube from the first box in my row and installed the new sensor but still, no water. When taking the old sensor out, I tested the water and it came through the smallest tubing just fine. I keep thinking I'm missing something very obvious. Is there a way to test or What to do?