
JR
another data point...JR. wrote: ↑Mon May 24, 2021 5:24 pm Scratching another one off my to do list, I used my new "Y" driver bits and took apart my previous sump pump. I was looking for a blocked air vent and found a ball bearing check valve. The ball was stuck up, sealing the vent hole, but it dropped easily when I touched it with a nail point. Shaking it the ball bearing appeared to move freely.
I reassembled it and in a test pull, it starts from pretty low, only a couple, inches from the impeller level. This seems better than before, while the ball bearing check valve air vent did not appear stuck very hard.
Looks like I have a like good spare sump pump.
I may need to repair the lightning damaged float level controller. It is a low tech design using a 555 and a few discrete components.
No hurry
JR
The redundancy doesn't hurt... I am starting to apply some hindsight at this apparent design problem. I was mainly seeing the air lock and refusal to pump in my testing outside the crawl space... after the pump is allowed to pull air, apparently it pressurized that air enough to hold the check valve vent closed.