A backwater valve is a one-way valve on the main sewer line that lets wastewater flow out of your house but closes if sewage tries to flow back in. Homes with basement drains, past backups, or plumbing below street level often benefit the most from having one.
How a Backwater Valve Works
Inside the valve is a flap that stays open while water flows out toward the sewer. If the public sewer fills up and water starts moving the wrong way, the flap closes. That helps keep sewage from rising through basement floor drains, toilets, and showers.
Most valves have an access cover so the flap can be checked and cleaned. The cover is usually set in the basement floor or in the yard near the house.
Which Homes May Need One
- Homes that have had a sewer backup before
- Houses with finished basements or basement bathrooms
- Homes where the lowest drain sits below the level of the street sewer
- Properties on low ground where water collects in heavy storms
Not every home needs one. A plumber can look at how your drains are laid out and whether a valve makes sense. In some places, a permit may be needed to install one.
Keeping It Working
A backwater valve is not set-and-forget. Debris, grease, or roots can keep the flap from closing all the way. Having it checked once a year, and after any backup, helps make sure it works when you need it. While the valve is closed during a backup, avoid using water in the house, since it has nowhere to go.
If sewage has already come into your home, the line and valve should be checked before the area is cleaned. Help with sewer backups includes finding out why it happened.
To ask whether a valve is right for your house, talk through your drain layout with a plumber or call JPR Plumbing at (833) 603-1840.