Hi All!

I have an HVAC issue I can't figure out. My 1st floor inside air handling unit is in the basement. It's been filling the pan with water, and kicking off the AC when the float switch trips. I thought it might be a faulty pump (mine isn't gravity draining, drains into a pump and pumps outside). Pump works fine. Then I thought my drip line was clogged. I snaked it, still fills the pan. Next I thought maybe the line is partially clogged. Snaked again and separated the pvc drain piping and put a funnel in line so I can see it dripping, just to monitor. Always dripping when the AC is running, no problem. 

I can check on it for days and it doesn't fill up; until it does again.

Then I thought; maybe the pump housing has a slow leak. It leaks out faster than the drain drip, slower than the speed I filled the pump when I find the pan full and manually fill it. Took it out and ran it on a clean surface; no leaks.