Key points
Keep the valve accessible, clean and able to move before the building sewer is under pressure.
- Follow the manufacturer’s inspection schedule
- Remove debris without damaging the flap or seals
- Confirm the access cover remains reachable
- Investigate recurring debris, damage or poor movement
What Toronto homeowners should know
A backwater valve is a mechanical device installed in the building sewer. Grease, paper, mineral deposits or damaged components can interfere with movement.
Maintenance usually requires opening the access chamber, inspecting and cleaning the internal components, and confirming that the flap moves and seals as designed.
When the valve closes during a sewer surcharge, stop using toilets, sinks, dishwashers and washing machines until normal drainage returns. An alarm can help occupants recognize closure.
Municipal information: When a subsidy or permit is relevant, confirm current requirements directly with the City of Toronto. This website is a private contractor resource.
Need a property-specific assessment?
Bring photos, past invoices, camera reports and details about when the symptom occurred.
Request an Assessment