Seal weep hole

[JEuriech]

My inspection yesterday had two split 5 year old Trane heat pumps. One air handler was in the second floor hall closet. The other air handler was in the garage.

When I went by the air handler in the garage, I could hear a gurgling sound as if air was being pulled through water. I found a small square hole by the bottom condensation pipe. (actually between the bottom right primary drain connection and the left secondary drain connection)

I have not been able to find the installer's guide for this model air handler. However, other Trane (American Standard) guides call this a "Seal weep hole".

What is a seal weep hole and what purpose does it have? Should I be able to hear water gurgling from it? The second floor air handler had no noise coming from it. (p-trap is under the unit in the stand area)

Thanks,

Jeff

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[Marc]

I've heard of seal weep holes on sealed water-pump bearings but not on condensate line connections for an air handler.

For an answer to the gurgling, I'd look for a trap on the condensate line. There's none shown in the photo, maybe it's in the AR cabinet below. It there's none then the gurgling might be from air navigating the condensate line towards the blower suction. Not a big deal as long as an air gap is present between the trap on the 3/4" condensate line and the plumber's trap.

Need to take a peek inside that RA cabinet.

Marc

[JEuriech]

Marc

The seal weep hole had water in it. However, water does not come out when the air handler is off. Condensation must drain pass the hole only.

The RA cabinet grill in the entry area was sealed with caulking and I was unable to take it off. However, I did try to take some pictures through the grill. They didn't turn out very well. I can see a p-trap and what looks like an air vent.

Jeff

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[Marc]

Ok. I see from photo #1 that the horiz section of 3/4 PVC, which has the trap in it, in closer to the camera than the other horiz section of pipe.

In photo #2, the vertical section of the pipe that has the trap in it first rises then terminates just a few inches shy of the filter.

I could be seeing this all wrong but it seems to me that the section of 3/4 PVC pipe that has the trap is not even connected to the drain pan inside the air handler. The other one, without a trap, is the one that's carrying condensate water. It's wrong, but that's another fish for your report - a minnow - and not related to the gurgling.

The gurgling might be from a partially clogged pan that allows the water level in the pan to be higher than the top of the primary drain opening. Sewer gas that the suction is drawing into the duct system via the un-trapped condensate line is gurgling through this water in the pan. My ears don't work but I've serviced these systems for decades and have felt that gurgle many, many times.

Marc