Stuck sparge but not in the typical sense

[Little_Lebowski]

I must have brewed 30+ batches in the current 10 gallon igloo cooler and false bottom ball valve set up and never once had a stuck or even slow sparge. Last brew day I got NOTHING to drain at all at the completion of the mash. Needless to say I was surprised and caught off guard.

So I diddled around with the tubing from th false bottom to the ball valve thinking it wore out over time and with heat and somehow linked with 15 lbs of grain on top and created some kind of vacuum.

I was very worried going in to today's brew that this would happen again and **** you not it did. This beer is almost 90% 2-row and no high protein adjunct. I also mashed with 5 gallons to thin it out.

PLEASE HELP

 

[day_trippr]

I'm betting your ball valve is plugged up. Have you tried underletting through that valve?

 

[Little_Lebowski]

Just figured it out. The bottom of my cooler is all hellish warped and domed upwards. Basically fits the dome of the false bottom like a glove and seals up the pickup tube. Time for a new cooler