Air Admittance Valve to S-tape Utility Sink

[niko6266]

Hi Everyone,

This issue has been causing us problems for years and I want to see if there is a fix for it. Our utility Sink has to be snaked every 3-4 months because the water drains so slowly. The sink fills up every time the washer drains and takes minutes to clear. When it does drain I do hear gurgling noises. This is the only drain in the entire house that has an issue.

I'd like to add an air admittance valve to see if it helps drain the water faster. I suspect when they built the house this was an afterthought. I did bring in a few plumbers over the years before I started to snake the drain myself and they all did the same thing and never addressed the issue.

Would someone be able to help me look at the parts that are needed to add the valve to this? I went yesterday to Home Depot and the person there suggested a Rubber flex tee but that seems to be more for PVC pipes and not for sink drains.

Here is a picture of the current setup

Thanks

 

[MicEd69]

That is a S-trap which is illegal. If you change that to a P-trap and add an AAV, it will improve your sink draining.

Any idea what the piping looks like below the floor?

 

[Twowaxhack]

AAVs will not help it drain better.

In fact, AAV’s protect the trap from the powerful action of S traps siphoning the water out of the trap.

The entire drain needs to be replaced or professionally cleaned.

 

[Twowaxhack]

I challenge anyone to set up a sink outside with an s trap vs ptrap and see which sink drains the fastest. I’ve done it and put that baby to bed years ago.

 

[niko6266]

AAVs will not help it drain better.

In fact, AAV’s protect the trap from the powerful action of S traps siphoning the water out of the trap.

The entire drain needs to be replaced or professionally cleaned.

I appreciate the response. I've brought in people and all they do is snake the drain. I was fed up with dropping 50-$100 I bought one from Home Depot and started doing it myself.

I've asked them how to improve this and no one could give me an answer. I want to try this to see if it helps. Worst case I have to put the S-trap back in again.

 

[niko6266]

That is a S-trap which is illegal. If you change that to a P-trap and add an AAV, it will improve your sink draining.

Any idea what the piping looks like below the floor?

It's all metal piping below. That metal pipe that is exposed is soldered onto the flange below it.

 

[Twowaxhack]

I appreciate the response. I've brought in people and all they do is snake the drain. I was fed up with dropping 50-$100 I bought one from Home Depot and started doing it myself.

I've asked them how to improve this and no one could give me an answer. I want to try this to see if it helps. Worst case I have to put the S-trap back in again.

Replace the drain, All of it.

 

[niko6266]

Replace the drain, All of it.

The drain goes into the ground so this isn't an option as it would probably cost thousands of dollars. If I have any luck with the air admittance valve I'll let everyone know.

 

[Twowaxhack]

The drain goes into the ground so this isn't an option as it would probably cost thousands of dollars. If I have any luck with the air admittance valve I'll let everyone know.

Where the drain goes doesn’t affect my recommendation. If what you’ve said is true then it’s time to replace the pipe.

But don’t let me crush your hopes and dreams.

S/traps drain great, so great it sucks all the water out of the trap. AAV’s allow the drain to suck air rather than sucking the water out of the trap. BUT THATS NOT YOUR PROBLEM.

 

[niko6266]

Where the drain goes doesn’t affect my recommendation. If what you’ve said is true then it’s time to replace the pipe.

But don’t let me crush your hopes and dreams.

S/traps drain great, so great it sucks all the water out of the trap. AAV’s allow the drain to suck air rather than sucking the water out of the trap. BUT THATS NOT YOUR PROBLEM.

Isn't is possible that this drain wasn't installed properly to meet up with one of our two air vents and is causing the problem? This issue has been going on for over 20 years.

I replaced the the two metal pipes you see in the picture around 5 years ago.

One thing I found during my slow draining is that when I pushed in an air pocket into the drain it started flowing better, but when the air pocket came back up it slowed down again.

 

[Twowaxhack]

The only way a vent will help a drain is if the drain is flowing into a sealed container. But it has to be an atmospheric vent and I’ll explain why.

For example….. If a toilet without a vent and it’s draining into a septic tank. If there’s no vent then the water cannot displace the air and the air has no where to go. The water will drain slow and bubbles will be expelled from the toilet as the air is slowly pushed out by the water.

Would an AAV help in the above scenario ? NO……because AAV’s let air INTO the system but the problem is there’s no where for AIR TO ESCAPE From the system.