Ace in Hole works, but wont discharge any water when connected as backup

^^^^ thanks...i am going to take the pump off again and search for the anti-airlock hole to see if a) it exists and b) its not blocked.

I take it that I absolutely need one, right? If I have to drill one, I will drill it in the coupler connection below the check valve of the backup pump.

I finally found the issue. The anti-airlock hole was plugged.

I must have read the manual many times, but there is no reference to the anti-airlock hole existing on the pump nor is there any indicator on any of the pictures. The only mention of the anti-airlock hole is in the troubleshooting guide...but what threw me for a loop is that I know I didnt put on in there, so I assumed it was for another model. This frustrates me, but it is solved now.

Thanks everyone for your input.

Put a cotter pin in that hole and it becomes self cleaning.