DIY guideBackwater valve
Find, inspect and clear the backwater valve
Find the cover in the basement floor, open it with the water off upstairs, check the flap swings freely, and clear the chamber so it can close when the sewer backs up.
- 20 to 40 min
- 7 steps
- Every step animated
7 steps
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Look in the basement floor near the front wall, often by the floor drain, for a round or square cover, sometimes clear.
Ask everyone not to run water or flush while the cover is off.
Unscrew or lift the cover and set it to one side.
Wear rubber gloves and goggles: what's inside is sewer water. Wash your hands after.Shine a light in and nudge the flap with a gloved hand: it should swing freely and settle back by itself.
Pick out anything caught in it, then rinse it with a bucket of water so nothing stops the flap closing.
Check the cover's rubber seal is in place, then put it back on tight.
A cracked or stuck flap, a cover you can't open, or sewer water standing in it: put the cover back and ask Handyman for a plumber.
What you need
- Rubber gloves and goggles
- A flashlight
- A bucket of water
- A screwdriver, for a screwed cover
- Old rags
Call a pro if
- The flap is cracked, stuck or missing
- Water is standing in the chamber
- The cover won't come off
- Sewage has backed up into the basement
Handyman says: Flap broken? I'll find a plumber.
Free for every home. Handyman asks a few questions, then books a pro it trusts.
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