To unblock a double sink, remove most standing water, clear only visible debris, seal one drain completely and plunge the other with a flat-bottomed sink plunger. If both bowls will not drain, the blockage is likely beyond where their outlets join, although the symptom does not confirm its location.
Steps to try
Stop adding water: Turn off the taps and do not run a connected dishwasher. Wear gloves and bail standing water into a bucket, leaving enough to cover the plunger’s rim. Keep wastewater contained and avoid splashes.
Remove visible debris: Lift out removable strainers and use tongs to remove material plainly within reach. Do not put your fingers or tools into the drain. If the sink has a food-waste disposer, do not reach inside it; isolate it according to the manufacturer’s instructions.
Seal the second bowl: Fit its plug firmly or hold a tightly packed wet cloth over the drain. Because the outlets are connected, an incomplete seal allows plunging pressure to escape through the other bowl.
Plunge the open drain: Centre a flat-bottomed sink plunger over the outlet, submerge its rim and maintain a complete seal. Use several controlled, firm strokes without lifting the rim. If water rises in the other bowl, improve its seal before trying again.
Test carefully: Remove the seal and run a small amount of warm tap water. If drainage improves but remains slow, repeat the process once or twice. Do not fill both bowls to test them.
If only one bowl is affected, debris may be near that bowl’s strainer or branch connection, but do not dismantle the pipework to investigate.
If you do not have a plunger
Remove only debris that is plainly accessible, or obtain a suitable sink plunger. Do not improvise with compressed air, force objects or a drain snake into the outlet, remove the trap, or dismantle fixed pipework. A plumber should assess work beyond the sink opening.
If chemical drain cleaner is already present, do not plunge or add another product: contaminated liquid may splash, and mixing products can cause a dangerous reaction. Keep away from the water and tell the plumber which product was used.
When to call a plumber
Stop using the sink and arrange professional help if correct plunging produces no improvement, the bowls refill immediately, the blockage returns, a pipe joint leaks, or another fixture or floor waste backs up. These signs may indicate a deeper obstruction but do not identify its exact location.
If wastewater overflows, stop using affected sinks, appliances and fixtures. Keep people and pets away, avoid contact, and do not attempt forceful snaking or pipe dismantling. If both bowls remain blocked, contact our Sydney plumbing team.