Good intentions but...

[Jim Luttrall]

I came across this yesterday. Looks like a home owner special or from a tech that had a "better idea" that he should have forgot.
There are two drain lines each with its own shallow running trap and no vent. One drain goes to the standard location and an additional one goes over to the sewer vent. And this was on a heat pump with the coil under negative pressure.

[Vern Heiler]

I didn't know the secondary drain was really the bleach injector port.

[Jerry Peck]

All with a running trap, which is not allowed anyway. :)

[Jim Luttrall]

All with a running trap, which is not allowed anyway. :)


There are two drain lines each with its own shallow running trap and no vent
Not just one running trap, but two! Of course only one is in the picture.
I basically said to have someone tear it out and do it right from scratch. I don't think I could begin to describe how to "correct" all that was wrong with the setup.

[Mitchell Toelle]

I came across this yesterday. Looks like a home owner special or from a tech that had a "better idea" that he should have forgot.
There are two drain lines each with its own shallow running trap and no vent. One drain goes to the standard location and an additional one goes over to the sewer vent. And this was on a heat pump with the coil under negative pressure.

If you look carefully, the riser that is labeled "bleach" appears to be lower than the other condensate exit. Therefore, it is probably the primary, not the secondary. Nor should it be a bleach receiver.

As you said, "can't begin to describe all that is wrong" and tear out, starting from scratch. But, plumb the primary as the "primary" and not as a bleach receptacle...and the secondary in a proper manner...

[Jim Luttrall]

I think the elevation of the primary and secondary is somewhat of an optical illusion but none the less, tear it all out and start over is the best bet. The installer went to lot of thought and trouble to come up with this, too bad they were a few french fries short of a happy meal.;)

[A.D. Miller]

All with a running trap, which is not allowed anyway. :)

JP: Can you elaborate or hold forth a bit on running traps and why they are not allowed?

[Jerry Peck]

JP: Can you elaborate or hold forth a bit on running traps and why they are not allowed?


Running traps are traps which have the inlet and outlet at the same elevation in relation to the trap, and, because they are "running" traps they have a tendency to self-siphon out from the flow through them.

They are not allowed because the manufacturers specifically state not to use them - it is in the installation instructions, plus they are not proper traps anyway.

[Matthew Klein]

Take a more intense look at the picture--heavy water stains in the pan below the unit, apparent repair to the lower corner of the unit possibly due to corrosion, directions to pour bleach into the unit's condensate pan. This unit has had significant condensate pan overflows in the past. The unit has apparently seen a lot of debris in the air stream or the drainage system is not functioning correctly. You said the coil plenum is under negative pressure. In that case, I suspect that air may be pulled through the condensate line, not allowing the unit to drain properly, particularly since the traps are running traps.