For a blocked commercial kitchen drain, stop using the sink and remove only standing water and loose debris that is safely reachable from the bowl or strainer. If no chemical cleaner has been used and there is no contaminated wastewater, you can try a sink plunger. Keep clear and call a licensed plumber if wastewater backs up, several fixtures are affected or the blockage remains.
Safe checks before calling a plumber
Try these limited steps in order, testing with a small amount of cold water after each one.
- Stop use: Keep staff away from the sink and affected food-preparation surfaces. Wear waterproof gloves if removing clean standing water, but do not touch wastewater or put your hand into the drain.
- Remove loose debris: Clear food scraps from the sink bowl or removable strainer without inserting tools into the pipework.
- Plunge only when safe: If there is no chemical cleaner or wastewater in the sink, use a flat-bottomed sink plunger. Seal the second outlet of a double sink, then plunge while maintaining the seal.
- Test cautiously: Run a small amount of cold water. Stop immediately if it rises, leaks from a joint or drains slowly.
If the sink has a powered waste-disposal unit, switch it off using its normal control and follow the manufacturer’s safety instructions. Never reach inside it, remove covers or attempt electrical work. Arrange qualified service if the unit appears to be involved.
Do not remove traps, open pipework or use powered drain-clearing equipment. Commercial kitchens may have grease-management, trade-waste or shared drainage systems that require professional diagnosis and cleaning.
Do not mix drain-cleaning chemicals or plunge a drain containing chemical cleaner. Corrosive liquid may splash onto skin or eyes. Follow the product label. If exposure occurs, call the Poisons Information Centre on 13 11 26; call 000 for an emergency.
When to call a plumber
Keep the sink out of use and contact a licensed plumber if:
- wastewater backs up or contamination is possible
- several fixtures drain slowly or overflow
- there is a strong sewage smell
- water leaks from a joint or nearby surface
- the blockage quickly returns
- pipework is damaged, displaced or concealed.
Recurring grease blockages can point to a deeper restriction or a maintenance problem, not just debris at the sink. Avoid contact with wastewater and isolate the affected area from food preparation. For a persistent or unsafe blockage, contact our licensed Sydney blocked-drain team.