Beckett CB151UL Condensate Pump

Hi,

I am trying to trouble shoot a Beckett CB151UL condensate pump.  I
found a pool of water next to my furnace and I suspect it is from the
condensate pump.  The water level in the reservoir was fairly high,
close to the brim.

I do not have experience working with pumps but while the pump was on
I removed the clip connecting the hose and there was enough pressure
for the water to shoot out like a fountain.  I was able to put the
tube back and the duckbill value correctly.

I have turned off my AC, and manually poured water into the
reservoir.  This started the pump but I don't see it pumping the water
out (I did see it pumping water out before I removed the tube).

I would appreciate if someone can help explain the puddle of water and
why I the pump is not pumping water out of the reservoir?  Also, is
there a owner's manual/troubleshooting manual I can locate online?
What other checks can I do?

Thanks.