What is a Backwater Valve?

Sewer Backwater Valves

Whenever there’s a sudden downpour, there’s a risk that your kitchen, bathroom or basement could experience a water backup problem. It’s bad enough if clean rainwater backs up in your basement; try to imagine dirty sewage filling your basement and ruining everything it touches.

Fortunately, you can help prevent this by installing one simple device: a backwater valve.

What is a backwater valve?

A backwater valve (sometimes called a backflow or sewer backup valve) is a valve you can install on your sewer line and is designed to allow water or sewage to flow only one way — out of your house. Sudden, heavy rainfall can overwhelm city sewer lines, causing water or sewage to flow back towards your home. A backwater valve prevents sewage from flowing backwards into your house during such events.

They can be installed in the initial new construction or retrofitted into existing homes. Installing during the initial construction is naturally much cheaper, costing around $250-500. To retrofit a backwater valve, it’s best to get a licensed plumber to review the layout of your home and its elevation in order to provide a price for the install.

The risk of water backup increases if there is a basement in your home, or if the ground floor is less than 12 inches above street level.

How does a backwater valve work?

How Does a Backwater Valve Work?
Diagram from Plumbing Today

Your home’s sewer system allows water and sewage to flow out of the house. A backwater valve stops water or sewage from flowing into your house should the main sewer line ever become overloaded or clogged with debris.

Inside the valve itself, there is a small flap that is normally open, allowing water to exit your home and any sewer gases to vent. There is a small floatation device on each side of the flap. If water or sewage starts to flow backwards into the house, the floaters cause the flap to lift up and close, thus preventing anything from entering your home.

When the water stops coming back towards the house, gravity will allow the flap to fall into the open position again, allowing water and sewage to resume flowing out of the house.

The valves often have a clear top so you can see if it is operating properly. There’s also a lid that you can remove for cleaning. Without a properly functioning backwater valve, sewage could come into the basement through a floor drain, sinks, tubs, and toilets.

What is The Difference between the clever cleanout and a backwater valve?

The Clever Cleanout and a backwater valve are similar in function but have several key differences. Both are easily accessible outside your home and help prevent flooding into your house, but only one allows you to continue using your home as normal.

When the backwater valve is closed, water can’t flow out of your house either. There is a certain amount of storage space in your plumbing system to account for this. But, you may not want to shower and run your washing machine or dishwasher all at once during a major rainstorm or snowmelt event. Since none of your wastewater will be able to escape with the backwater valve closed, you could wind up flooding your own house.

With the Clever Cleanout, wastewater can continue flowing out of your home while protecting your home from inflow of sewage and water at the same time. If sewage is backed up, it will drain through the Clever Cleanout until the reason for the backup is fixed. If someone in your home (or business) uses the toilet or washes their hands while there is a backup of water or sewage, it will continue to drain through the Clever Cleanout and continue protecting your home from flooding.

What should you do when something goes wrong?

If you have a properly positioned and installed backwater valve, you shouldn’t have many problems—as long as you have been maintaining it properly.

Things can get stuck inside the valve, preventing it from closing. Sharp items moving through can also damage the valve. Proper, regular maintenance can catch these issues before there is a serious problem.

If you’re concerned about properly maintaining a backwater valve and would rather have the confidence of a hassle-free solution, try the Clever Cleanout. It’s easy to install and will give you the peace of mind you need to protect your investment at home.

Shopping Cart
Scroll to Top