Sink Will Not Drain - Conversion of 2 Basin Stainless Kitchen Sink to 1 Basin Porcelain Kitchen Sink with Disposal.

[WalterJ]

Sink is on Peninsula and 5 feet from vent stack in wall to roof.

Before Conversion: 2 Basin Stainless Kitchen Sink, 2" PVC Exit Drain, to 2" PVC P-Trap, to PVC Adapter 2" to 1 1/2" Kitchen, to 1 1/2" Kitchen Adjustable T and Fittings, 1 Side Disposal = Drains Perfect.

After Conversion: 1 Basin Porcelain Kitchen Sink with Disposal
Attempt 1 = no under-cabinet vertical pipe without Air Admittance Valve,
same 2" PVC Exit Drain, to same 2" PVC P-Trap, to same PVC Adapter 2" to 1 1/2" Kitchen, to NEW 1 1/2" Kitchen Elbow and Fittings, to Disposal = NO GOOD. Backs up after 2 minutes, takes 1 hour to dissipate.

Attempt 2 = YES under-cabinet vertical pipe WITH Air Admittance Valve (Oatey Sure-Vent, Studor Mini-Vent),
same 2" PVC Exit Drain, to same 2" PVC P-Trap, to same PVC Adapter 2" to 1 1/2" Kitchen, to SAME 1 1/2" Kitchen Adjustable T and Fittings, to Disposal and vent pipe = NO GOOD. Backs up after 2 minutes, takes 1 hour to dissipate.

What is the problem? Worked fine with 2 basins.

Called professional plumber for consultation. Said Vent Stack in wall 5 feet from drain is good and within code, no need for dangerous Air Admittance Valve. Recommended reduce to 1 1/2" Kitchen P-Trap, claiming problem was 2" PVC P-Trap was too large. Why? Hard to believe. 2" P-Trap Worked fine with 2 basins.

(yes, snaked both drain and cleanout just to be sure)

 

[WalterJ]

Yes, Porcelain Sink is a bit deeper.

 

[Sponsor]

 

[Reach4]

Push one of the rubber flaps open as you try to drain the sink. If that works around the problem, you can trim the rubber flaps to allow a little air to come thru the flaps easier.

 

[John Gayewski]

I agree with the plumber. And it's probably the flaps.

My sink does it all the time. I just turn thr disposal on and it drains just fine. I don't like opening the flaps and I'm too lazy to change it.

 

[WalterJ]

I assume you guys are referring to the "flaps" on the Air Admittance Valve? if so, I have Air Admittance Valve removed, so I know it cannot be the problem. What other "flaps" are there? (p.s. running the disposal does not help...and have not put any food down there yet).

Is it plumbed right? Do I need an Air Admittance Valve on the T if the vent stack is 5 feet away?

 

[Reach4]

I assume you guys are referring to the "flaps" on the Air Admittance Valve? if so, I have Air Admittance Valve removed, so I know it cannot be the problem. What other "flaps" are there? (p.s. running the disposal does not help...and have not put any food down there yet).

When you look from above into the sink bowl into the disposal, there is a black rubber piece. It has flaps.

 

[Jeff H Young]

disagree a 2 inch trap has nothing to do with why water wont drain it could be 1 inch or 6 inch its going to drain.
sounds like a stoppage

 

[WalterJ]

Hi Guys - Still Have Exceptional Low Drain Flow in Kitchen.
Current Conclusion: For Some Strange Reason, Drain Became Blocked at the same time sink change unrelated!?!?!

Facts Review:
Conversion of 2 Basin Shallow Stainless with disposal to 1 Basin Deep Ceramic with disposal. (ground level of house)
All was working fine with 2 Basin Sink.
Again, all the 2" is/was existing. I did not add any 2".
Sink is on Peninsula, Vent Stack is 5 feet from Sink.
Vent Stack is a vertical 90 degree T up, and I believe the drain goes 90 degree down at T to get to below floor level.
Water can run for about 45-90 seconds, then backs up.

Efforts:
1. Removed T and plumbed disposal directly to 2" P-Trap. - no good/change.
2. Put T back and added Vent Stack in cabinet. no good/change.
3. Removed all 1 1/2 pipes, ran Home Coil Spring Snake in 2" drain to vent T (5feet). - no good/change.
3. Home Coil Spring Snake in Adjacent 2" Clean Out (8feet on a different angel). - no good/change.
4. Called and Paid Radiant Plumbing Service. They advised that all 2" pipe and P-Trap be changed to 1 1/2 kitchen pipe (I do not buy this theory).
5. Removed all 1 1/2 pipes, ran garden hose into 2" drain. BINGO, Water can run for about 45-90 seconds, then backs up. PROBLEM IS NOT SINK, DISPOSAL, P-Trap, Pipe Size, or Reducer.
6. Removed all 1 1/2 pipes, rented and ran Commercial Coil Spring Snake in 2" drain to (33feet, which would take it 6 feet past front door)(or up the vent stack . - no good/change.
7. Purchased Drain Bladder 1-2" version. was able to stuff in 2" drain only to vent T (5feet). - no good/change. (it did not hold back the water, got backflow under the sink after 45 seconds.)
8. Put garden hose into other sink drain on ground level (powder). Drains fine. Conclude Kitchen Sink clog is before where Powder Sink joins Kitchen Sink drain.

All Variables or potential causes. (starting from user perspective downward):

• Rubber Splash Guard - nope, removed.
• Disposal - nope, removed.
• Disposal and bottom of sink is now 5" lower than before leaving only 1-2" of downward run to drain - nope, removed.
• P-Trap - nope, removed.
• Anything I did - nope, removed.
• Venting - nope, same as before.
• 33 feet drain coil snaked - no improvement. (possible that snake went UP T to vent and not down T drain to below floor level)
• 5 feet drain bladder - no improvement.
• All other plumbing in house fine.
  
  
  
  
  

 

[Jeff H Young]

drain stoppage forget the vents .

effort number 4 radiant plumbing suggestion might need doing but wont help at all with a drain stoppage

if water runs for 45 seconds then backs up obviously there is a problem downstream so your on track don't get side tracked on issues unrelated. need to run a snake down maybe your snake is going up a vent (sounds like there is some mickey mouse plumbing work) rather than down .
the only drain that plugs is kitchen? you can run hose down any drain full blast for indefinite time? you need to snake it again.
why only 33 feet snaking? you need to run the snake through the clog not up a vent i know its hard but if your going up a vent your not doing anything

 

[Reach4]

Man, you have been having a time.

Water can run for about 45-90 seconds, then backs up.

https://www.inchcalculator.com/pipe-volume-calculator/ is a calculator that tells how much water would fill a pipe.

So using that, if I assume 2 inch ID actual, and if there is a hard clog after 10 ft of pipe, then you would fill the pipe with 1.632 gallons of water.

https://www.omnicalculator.com/construction/pipe-volume is a more sophisticated calculator. If you again enter 2 inch ID but jump down to the volume (which you can change to gallons), then the length to the clog will appear.

When measuring for backup, I would gauge by when the disposal starts backing up. We don't want to compute the volume of the disposal chamber.

But the run may not be a simple pipe, and may have branches. Still, the volume of water that causes a backup can give you a better idea.

They advised that all 2" pipe and P-Trap be changed to 1 1/2 kitchen pipe (I do not buy this theory).

If there was a trap adapter at the wall, rather than a glued trap, access for snaking would have been easier.

33 feet drain coil snaked - no improvement. (possible that snake went UP T to vent and not down T drain to below floor level)

(yes, snaked both drain and cleanout just to be sure)

You would think that from the cleanout you could be sure that the snake went down rather than up.

I assume your kitchen is on a slab.

5 feet drain bladder - no improvement.

I wonder if pushing that down the vent pipe from the roof would work. That would only work if the vent pipe was right above the santee. I used Brasscraft drain bladders. I wonder if that would seal better, but you maybe couldn't get the drain bladder to a straight section of pipe.

 

[WalterJ]

drain stoppage forget the vents .

effort number 4 radiant plumbing suggestion might need doing but wont help at all with a drain stoppage

if water runs for 45 seconds then backs up obviously there is a problem downstream so your on track dont get side tracked on issues unrelated. need to run a snake down maybe your snake is going up a vent (sounds like there is some mickey mouse plumbing work) rather than down .
the only drain that plugs is kitchen? you can run hose down any drain full blast for indefinate time? you need to snake it again.
why only 33 feet snakeing? you need to run the snake through the clog not up a vent i know its hard but if your going up a vent your not doing anything

Thanks Jeff and Reach4
- 33 Feet of drain coil snake was all it would take, it would not take the extra 17 feet of the 50 feet total. I pushed and twisted as hard as I could. that 33 feet if it went horizontal ) would take it 6 feet past front door.
- The Drain in this cabinet peninsula is 1 foot off the slab, runs 5 feet into a "pillar wall", I have made a hole in "pillar wall" and see the T with the vent pipe going up past the hole I am looking in, and with NEW HAND MIRROR, I can see drain goes 90 degree downward into slab, then likely 90 degree to level out. Summary = I am dealing with THREE (3) 90 degree elbows!!
- Cleanout is not near the Drain T or "Pillar Wall". The Cleanout is located 6" below the drain, runs parallel for 4 feet, then 45 degree right turn and does NOT seem to take the same path as the drain, which is weird.

- Yes, kitchen is only sink not draining. Powder room sink and toilet on same floor.
- Yes, retrieved snake did have odor of intersecting with a toilet drain, but definitely not conclusive.
- Yes, on a cement slab.
- 2 story home, so roof vent is too high to access and cannot put snake down vent pipe.
- Yes, thanks Reach4, I LOVE the idea of calculating the volume to determine the clog distance. Will do.
- Yes, if there was a trap adapter at the wall, rather than a glued trap, access for snaking would have been easier. I am ready to cut off all 2" parts, but I am still faced with 3 90 degree elbows.

 

[Jeff H Young]

cut vent pipe ( in "pillar wall" )and run snake down might be an idea? sounds like you opened up wall since you have knowledge what's inside.
if there is a crawl space go underneath and cut pipe

 

[WalterJ]

SOLVED-RESOLVED!
Hired pro plumber.
Yes, there are 3 90 elbows. Yes, your snake was likely going up the vent.
He had scope and we could see clog about 15-20'.
Because of the elbows, his large snake and powerful tools would not make it after 3 attempts and different heads.
Solution: Cut off all extra 2" fittings for better access, used my thinner "home" snake, Success.
Conclusion: the drop in temperature of pipe and slab and blob was a coincidence to my plumbing project.
Topic Closed - thank you all.

 

[Jeff H Young]

yep I knew it!