Hello folks, 1st time seeing this: RUUD UGRA 60K
installed 5yrs ago, problem just started.
will run 10min until water fills secondary to the point the LPS opens.
will shut down, here is what is strange: water stays in the secondary, cleared the trap-still does it, changed the trap-still does it, removed the drain line (after the trap & little vent stack) still holds the water! removed the black secondary drain at the trap & all the water pours out (appears the trap itself is holding the water in all the way up to the secondary)
RUUD tech support advised multiple hoses "Teed" into drainline on floor will cause, however,1: it worked for 5 yrs 2: will not drain even with floor drain disconnected 3: the install boys did 100's like this (evaporator & intake drainline manifolded on floor)

sounds like condensate is being sucked up as it is running (gurgle gurgle) then when shut off, it all stays in the system
(furnace grade is pretty level, not graded to rear or side at all)

looks like the weight of the water in the system cannot overcome the trap to drain, even after inducer is off!
scratching head