AC question?

[Hooverfb]

So theres a unit in the attic... and I dont see a trap or opening to flush the drainage pipe. So my first thought was ah, I should change that and put in a t trap.

Then I was looking and realized, I dont really see a primary and secondary drainage. Just looks like it tuns to the pan underneath the unit. So I started looking around the house for another drainage outlet... to no avail. Is it common here (or for homes built in the 80s) to only have one drainage line?
Second question... I put some vinegar in that pan to clear the line of stuff, and since then it has drained well... but the vent that runs directly under it has been dripping. Guessing i need an AC guy as this ain't my forte, so any AC guys in katy or ones you recommend?

[kmitchl]

Even homes built in the 80's had a primary drain piped to the home drain system and a secondary drain piped to a drain pan and from the drain pan to a open drain through the soffit in front of a window so you can see when the primary drain is clogged. When I lived in Katy I used Bill Wallace, Wallace AC. 281-391-8081

[shiner78]

Very odd. There has to be a primary drain. If not there would be water in the pan. Calling a/c experts.

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[double bogey]

There is most likely a drain on the other side of the unit. As described above: you will have one drain (main) going to an approved location, like a washing machine drain or a sink connection. The auxiliary drain usually runs to an outdoor location that is easily visible in the event of a main line clog.
If there is any water in the pan under the unit (emergency or auxiliary pan), you need to locate the main drain. Cut the line, blow in both directions til clear, put a coupling or rubber splice back in its place.


The main ac drain cannot direct connect to the sewer system, as sewer gas can enter the house if a trap dries out. It will connect under a sink before the trap, or to a washing machine connection before the trap. The larger traps are less likely to dry out, as they will be use often, and in the winter the ac drain will not be used.

[Hooverfb]

There is most likely a drain on the other side of the unit. As described above: you will have one drain (main) going to an approved location, like a washing machine drain or a sink connection. The auxiliary drain usually runs to an outdoor location that is easily visible in the event of a main line clog.
If there is any water in the pan under the unit (emergency or auxiliary pan), you need to locate the main drain. Cut the line, blow in both directions til clear, put a coupling or rubber splice back in its place.


The main ac drain cannot direct connect to the sewer system, as sewer gas can enter the house if a trap dries out. It will connect under a sink before the trap, or to a washing machine connection before the trap. The larger traps are less likely to dry out, as they will be use often, and in the winter the ac drain will not be used.

Okay. Sounds like I need to try to get around to the other side of the unit then. Since we bought the house I can only remember it draining from the auxiliary. The main must be going to this drain outside that I know connects to the water heater, as that's the only other outlet I can find.

[bowhntrmatt]

Primary comes off the unit. It’s often insulated. Secondary goes to the pan under the unit. This pan should never have water and if it does, you have problems. I’d say get a pro out there.

[double bogey]

The main drain line will be on the side of the coil / unit that the refrigerant lines come off of. typically. Sometimes the main will drain to an approve drain, and they will pipe the auxiliary off the coil to the pan underneath. Sometimes this causes problems. This drain is a little higher in the coil pan than the main, and turbulence will sometimes cause water to blow into this line, into the aux. pan. I don't hook them up that way.

Signs of rust in the auxiliary pan means an ongoing issue, and I would get a pro to look into it. System should never have water in the auxiliary pan, unless a drain is clogged.