Strange waste pipe routing under bathroom sink

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flipsensazn

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See attached photo. I'm attempting to unclog a bathroom sink. Plunging was not successful and neither the baking soda / vinegar / boiling water.

Next, I was going to attempt to snake it. Removed all the PVC piping you see in the picture, but not able to get the drain snake more than 1 foot in. Never seen this type of waste pipe before it seems to be routing in two directions?? All other waste pipes in our home just go directly into the wall (like normal).

Any ideas?
 

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Geofd

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Your right, it's not piped correctly, without opening walls and repiping you won't make it right I would loosen that 2 band coupling
And snake were it enters the copper
 

flipsensazn

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Your right, it's not piped correctly, without opening walls and repiping you won't make it right I would loosen that 2 band coupling
And snake were it enters the copper
So, I removed the 2 band coupling and attempted to snake where it enters the copper.. I first went back toward the wall and found that it was actually going upward (I could hear it rattling as it snaked upward on the back wall).. So I figured that was likely the vent.. Unfortunately, the snake does not fit going the other way (the 1/2" piping you see in the picture).. Truly mind blowing if that is where the water is expected to exit.. some large copper pieces were already coming out when initially trying to snake that direction..
 

flipsensazn

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Put a slight bed in your cable so it has a chance to fall down the drain,is there access from the floor below????
I will try again and see if it can go down, there is no access from floor below unfortunately..

Can someone explain why there is a separate 1" copper coming out then back into the wall?
 

MicEd69

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I can only guess, but it appears someone tried to vent the sink with the 1/2" line. This is a real mess, and it will never operate properly. Even if it has been fine for years, once it is clogged, it will not take long for it to repeat as this is TOTALLY wrong, IMHO. Especially if the larger line does go up inside the wall as you have indicated. This is one of the worst installations I've ever seen.

I would tear into the wall and re-pipe the drain properly. Just unclogging it now, if you even can, won't make this installation workable in the long run.
 

flipsensazn

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I can only guess, but it appears someone tried to vent the sink with the 1/2" line. This is a real mess, and it will never operate properly. Even if it has been fine for years, once it is clogged, it will not take long for it to repeat as this is TOTALLY wrong, IMHO. Especially if the larger line does go up inside the wall as you have indicated. This is one of the worst installations I've ever seen.

I would tear into the wall and re-pipe the drain properly. Just unclogging it now, if you even can, won't make this installation workable in the long run.
Thanks for the response - I will be hiring a professional to re-pipe correctly..

Another strange thing we noticed - When I siphon out most of the water from the sink (down to the trap), the sink will fill up again half way after about 4-5 hours.. Where is that water coming from? We never ran the sink faucet or anything..
 

Twowaxhack

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Thanks for the response - I will be hiring a professional to re-pipe correctly..

Another strange thing we noticed - When I siphon out most of the water from the sink (down to the trap), the sink will fill up again half way after about 4-5 hours.. Where is that water coming from? We never ran the sink faucet or anything..
The drain must be a shared line with another fixture or appliance that discharges water.
 

MicEd69

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The drain must be a shared line with another fixture or appliance that discharges water.
Or the way the drain is "vented", that vent line could be attached to a drain line and the idiot was trying to wet vent this sink. Same thing only the water is coming through the vent line instead of the drain line.

One thing is for sure, it's not even close to being a proper plumbing installation.
 

flipsensazn

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I received a ballpark estimate between $650-850 to reconfigure the drain. Does not include sheetrock repair. Is this reasonable?
 

MicEd69

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Seems quite reasonable to me. The range is probably based on the limited knowledge of what needs to be done once the wall is opened up.
 

Twowaxhack

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Or the way the drain is "vented", that vent line could be attached to a drain line and the idiot was trying to wet vent this sink. Same thing only the water is coming through the vent line instead of the drain line.

One thing is for sure, it's not even close to being a proper plumbing installation.
I don’t think they had a plan or a clue.
 

flipsensazn

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Or the way the drain is "vented", that vent line could be attached to a drain line and the idiot was trying to wet vent this sink. Same thing only the water is coming through the vent line instead of the drain line.

One thing is for sure, it's not even close to being a proper plumbing installation.

so the plumber believes this may be the AC condensation line. This actually makes sense since the HVAC unit is directly above in the attic. However, it is still not plumbed correctly.
 

flipsensazn

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sure enough, I go up into the attic and it is routed down that same wall.. mystery solved!

drain.jpg
 

Twowaxhack

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Correct, the drain was shared with another fixture or appliance that discharges water.

In this case it was the AC condensation.
 

Twowaxhack

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You have a Delta pop up drain attached to that lavatory.

Those are some of the best if not the best pop up drain that money can buy.

I don’t like AC condensate being connected on the drain side of the trap. I’d rather see it go outside or be indirect connected on the house side of the P-trap
 
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