Sink Will Not Drain-Conversion 2Basin to 1Basin KitchenSinkW/Disposal.

[WalterJ]

New Sink Will Not Drain - Conversion of 2 Basin Stainless Kitchen Sink to 1 Basin Porcelain Kitchen Sink with Disposal.
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. Yes, Porcelain Sink is a bit deeper.
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)

 

[Timmy D]

I’m struggling to remember but once had a similar issue. How’s the sink overflow connected?

Is it connected to the macerator?

Most insinkerators have a special discharge pipe which should connect directly to the trap.

Yours looks like it comes horizontal out of the unit to the trap.

Disconnect the trap, pour water/use hose pipe to send water down the waste pipe. If it goes free, you’ve proven the pipe is clear.

Then put container at end of current macerator discharge pipe and let the sink go. Water flows? Proven that bit of pipe.

I suspect it’s getting air locked.

Take air admittance valve off and try it.

 

[WalterJ]

I think Timmy D deserves a gold star.
Air Admittance Valve is already off - nope.
The T is installed with the baffle going the right way - nope.
The water flow nicely directly out of disposal into container - nope.
A garden hose directly into the 2" PVC drain pipe - BINGO, ran for 1 minute then backed out!
Blockage.
Hence, I conclude, for some stupid reason, something weird changed when I swapped the sinks, unrelated to my 3 attempts at plumbing.
Going to look into buying or renting endoscope.

 

[Timmy D]

I’m struggling to remember but once had a similar issue. How’s the sink overflow connected?

Is it connected to the macerator?

I think Timmy D deserves a gold star.
Air Admittance Valve is already off - nope.
The T is installed with the baffle going the right way - nope.
The water flow nicely directly out of disposal into container - nope.
A garden hose directly into the 2" PVC drain pipe - BINGO, ran for 1 minute then backed out!
Blockage.
Hence, I conclude, for some stupid reason, something weird changed when I swapped the sinks, unrelated to my 3 attempts at plumbing.
Going to look into buying or renting endoscope.

Good job.

Wouldn’t bother with a camera. Get a drain spring and give it large.

 

[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.
  
  
  
  
  

 

[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.

 

[Timmy D]

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.

Appreciate the updates.