Place a bucket under your sink. Unscrew the slip nuts on the U-shaped pipe. Clear out any debris. Often, the clog is right here, not outside. Reassemble and test.
| Symptom | Likely Cause | DIY Solution | | :--- | :--- | :--- | | | Blocked vent or partial clog. | Check vent stack on roof or install AAV under sink. | | Slow Drain | Grease buildup or debris. | Plunge, then snake. Use enzyme cleaner weekly. | | No Drainage | Full clog or frozen pipe. | Snake the line. If winter, check for ice outside. | | Bad Smell (Inside) | Dry P-trap or rotted gasket. | Run water to fill trap. Check seals under sink. | | Bad Smell (Outside) | Dirty Gully / Broken Seal. | Clean the gully basin. Check the "grate seal." | | Water Leaks on Wall | Pipe disconnected from gully. | Reattach pipe and secure with brackets. | kitchen sink outside drain
Older outside drain setups often lack proper venting. Without a vent, water siphons out of the P-trap, letting sewer gas in. Place a bucket under your sink