What Is a Back Water Valve ?

The most effective method to prevent the backflow of sewer water is a simple device called a backwater valve. Installation of a backwater valve prevents water from traveling back into your home as it is a one-way valve.

Features and benefits:

“Normally-open design” offers zero flow restriction

“Normally-open design” allows free circulation of air through the Plumbing System

“Clear Lid” easy visual inspection of unit

“Built-in main-sewer cleanout”   allows auguring of sewer

Gate Function

Gate is fitted with closed cell polyethylene floats, this flotation material is impervious to sewage and will not become water logged (gate design locks floats in place)

Upon a slow reversal flow, water rises in the body and the gate starts to float (lift). Once the gate starts to lift the water flow in turn pushes the gate into the gate position.

Upon a quick reversal: The gate is fitted with 45 degree angles on the front which act as wings, upon quick reversal action water is diverted into the wing area through the flow channels. Water then pushes up on the 45 degree angles causing the gate to quickly close.

O-ring is used on the body for positive seal.

Built-in Sewer Cleanout

The built-in sewer clean out is downstream of the gate, a sewer tape will not catch on the gate when feeding or retrieving the cable

Bolted Gasketed Cover

Nuts and Bolts are Stainless Steel

Polycarbonate transparent lid provides a visual inspection of the unit at all times


CSA   B181 (ABS)     B182 (PVC)

UPC   IAPMO       PS-38 Standard


Developed in 1997

Over 400,000 in the ground 

Used throughout Canada, and certain parts of the US


Backwater valves are mechanical devices sitting in a sewage environment, and regular inspections are required. To ensure the satisfactory performance of the backwater valve follow the procedures listed below.

1. Remove the cleanout plug on the top of the valve and do a visual inspection.

2. Take a flashlight or trouble light to properly see inside the valve body.

3. Inspect for debris build-up on the body, gate and beneath the gate.

4. If debris build-up is found flush clean.

5. Inspect o-ring and replace if necessary.  The valve’s gate seals against

    an o-ring on the body ( in the closed position).

6. Ensure gate freely moves up and down.

7. Reinstall cleanout plug.

On models fitted with closed cell polyethylene floats, check the condition of floats and replace as necessary. * Note: these floats are located on both sides of the gate and are protected from sewage contamination by the sidewalls of the gate and body (long-life cycle, impervious to sewage). CSA certified floats. source: http://backwatervalve.com

How do I Have a Backwater Valve Installed

In most cases you will need a certified plumber to install a backwater valve for you. Installation involved removing concrete or flooring around your current sewage line and cutting and replacing sections of pipes. 

The cost of having a backwater valve installed in your home varies, but it will likely be around $1,500 to 1700$ for the entire installation. Some municipalities offer subsidies to cover some of the cost of installation. Call your local city council to find out about any subsidies that might be available in your area.

 Does Back Water Valve Can it Reduce My Home Insurance Rates?


 There are a number of new and existing home insurance discounts that require you you have this device. Not to mention that it just might save your basement one day.

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