bowl will not empty when I flush it, especially solids; what's
it can be attributed to either the 1228CW flapper valve or
C253 joker valve.
some instances it may have debris caught in the flapper valve,
or in the joker valve, which may be displaced by continued
pumping of the head. Then remove the discharge fitting at the
rear of the pump (1222AW) and remove and clean the joker valve
that doesn't work, do the same with the flapper valve (1228CW).
If neither works, replace both parts.
some installations it we have found that a small amount of
back pressure will improve the operation of the toilet. This
is accomplished by adding a vented loop in the discharge line,
approximately the height of the toilet bowl.