lennox drain problems

[scacguy]

has anyone had problems with lennox CB26UH air handlers.we have had several so far.

[croft1972]

We've found that open return units tend to hold water in them.

[sheetmtlman]

what's the problem?

[Milk man]

upflow or downflow?

Trapped or not?

[mook531]

dont use them...we use cb30's....and no problems with them

[scacguy]

application is horz/lennox tells us that 3 corners must be raised 1/4 inch to pitch towards corner with drain. a tee must be installed after trap with no cap so it is a vent.lennox says primary pan is only supposed to hold 2 tablespoons of water.several ones with long runs on drainline have installed condensate pumps &still have return boxes with water &wet ceilings.no room for error.they should have seen this being a problem since this is the cheap builders model& installed by subs that dont speak english in trac homes

[cde72]

Vents after traps are always good, the same reason plumbers must run vents right after traps in DWV. I always vent the tee with a length of 3/4 pipe that extends above the height of the primary pan so that if the drain is clogged between the trap and the "daylight", overflow water comes out of the primary and hopefully into the secondary as opposed to the floor or insulation in a horizontal application.