Strange plumbing setup

[Etheric]

So I'm a homeowner, and I redid the sink and under-sink plumbing in the guest bathroom no problem. I was encouraged by this, wanted to learn more, and decided to take a crack at our master bathroom sink, and that's been nothing but frustration so far.

The master bathroom was half-way remodeled by contractors hired by my wife's parents. They tried to renegotiate wages halfway through with me (not the person who hired them and was paying them) I told them they were talking to the wrong person and then my wife's parents told them to shove off. They were nice guys and it's a frustrating way to end a business relationship, but whatever, out of my hands now. They had already finished redoing the drywall (thank goodness) and I installed toilet and tile just fine. However they took all the under-sink plumbing with them (or threw it away) and I don't have a template to figure out what in the world is going on.

The plumbing from the wall is set up for a single vanity, I really want to find out how to convert it to a double vanity, but we just want a sink in the master bath now, so we picked up a cheap vanity from Home Depot knowing we'll be giving it to Habitat in a year or two anyway.

Single vanity bathroom sounds simple right? 1 1/4" sink extender, p-trap, then into the wall. A couple of hoses to bring the water in to the sink and voila.

Except that 1) the wall drain is a 4" pipe, and 2) the A/C drip pan's primary line drains into the master bathroom with a pipe that looks to be 1" in diameter.

The 4" pipe wasn't much of a problem, just buy an adapter. However, bringing in the A/C drip into the system is driving me crazy. Home Depot and Lowe's don't seem to stock anything in 1 1/4" that takes in extra lines (like a T), and when I go to 1 1/2", the T has threads on all three sides, so it can't connect to the p-trap. I currently have a 1 1/4" flexible hose, with a metal strap and a rubber glove (as a washer) holding it onto the drip line and the other end of the hose taped into my bathtub. It's not pretty. I've been to a specialty plumbing store, but it isn't like they have the parts out for me to browse through and the staff didn't seem too interested in helping me figure out what I needed. Do you guys have any clues?

 

[Bluebinky]

Oh boy,

Not a real plumber here, but here's my $.02

Even though it's done all the time, you can't/shouldn't *directly* connect the condensate drain to the sewer. The problem is that sewer gas can back up into the AC air stream.

To connect to a drain pipe, you need:
- a trap, with some way to keep it full year round.
- after the trap, a vent going up, and the drain going down. The trap doesn't need to go through the roof, it's just to keep you from having an "s-trap".
- the drain should then be *indirectly* connected to another trap. Indirectly means an air break (small pipe inside a bigger pipe), or an air gap (upper drain ends short of the lower drain pipe). The gap vs break part is debatable IMHO. You need to make sure that if you have a clog, the indirect connection doesn't cause a mess.

You can also just end the condensate drain above the rim of the vanity (very ugly), floor drain, or laundry tub... The upper trap is not so critical with this approach, unless the drain goes to an unconditioned space.

Is the AC coil in the attic? If so, you might want to consider piping it outside to a flower garden or dry well. If you have a condensing furnace, freezing can be an issue if you drain it outside.

 

[Sponsor]

 

[Etheric]

The coil is in the attic, midway on the left wall, it has a long pipe running from it all the way to the rear exterior wall, dropping down and into the master bath, exiting into the master bath from the same wall as the sink sewer drain, just several inches above it and to the side. The backup pan drain exits from the eaves to the side of the home on the exterior, but the primary drain goes to the bathroom. I've lived in my fair share of houses, but never one that drained into the bathroom like this. Maybe it's something more common in late-nineties homes here in Texas.

The drip pipe in the attic has several vents coming up from it as it crosses the attic. I'm assuming that's for the sewer gas buildup you were talking about. Also, although we're on the city sewage lines, we're so close to the same level or slightly below them that when the house was built, they just dug a pit and installed a sump pump to pump the sewage up to the street (we're the second owners, so I'm finding out a lot of things as we fix this place up), so I guess we don't have as much of a sewer gas backup problem as most people do. Because of our ignorance (and the contractor dispute) we had the toilet drain uncovered and without a plug for almost nine months and never noticed a problem.

So I bought some converters and have a set of plumbing for the bathroom at 1 1/2", and I picked up a branch tailpipe to slip in there below the sink and above the p-trap thinking I could get a rubber hose and run that from the ac drip to the spigot on the tailpipe you normally put the dishwasher line on. Am I on the right track here, or is this going to blow me up?

 

[Jimbo]

A condensate drain must connect above a trap. WHENEVER it is done otherwise, the result is sewer odors being sucked into the ventilation system, so just DON'T.
It is quite common to connect it above the trap in a lavatory sink, using a wye tailpiece and some a flexible connector. The hardware store should have all those items.

At the air handler, you should see two drains, one exiting the air handler just slightly higher than the other. The low one is the main drain....that should go to the trap as we mentioned. The upper one is a "tell-tale". It will carry water if the main drain gets plugged. It should drain to someplace obvious and visible, like directly over the coffee table! Because if you get a clog and get water backing up into the air handler unnoticed...serious damage may result.

 

[Bluebinky]

As a non-pro, I don't want to say right or wrong -- but it sounds OK. Might even be "correct"...

None of the professionals have a suggestion/comment?

 

[Cacher_Chick]

A sink tailpiece with a dishwasher connection is a fine way to drain condensate. It would be easier to comment on the rest of your questions if we could see it. Pictures would help.

 

[hj]

I don't know what you mean by a 4" pipe in the wall, or how you are measuring it, but the condensate line connects to a 1 1/4" threaded branch tailpiece, which you screw into the bottom of your brass sink drain. You connect from the pipe at the wall to the "branch T" with a piece of hose and hose clamps.