Does an outdoor backwater valve have a published price in Ontario?

We found only one published Ontario contractor price page for an outdoor backwater valve, so no range is shown for it here. An interior retrofit is a different job; published Ontario contractor pricing puts that at about $1,500 to $4,500.

An outdoor storm valve means digging, so ask for a quote that itemizes the valve, the excavation and reinstatement of the yard, the permit, and the plumbing labour. Separate lines are the only way to compare two quotes, and the City's rebate application asks for a paid, itemized invoice.

The City of Ottawa says a building permit is required to install protective plumbing devices, which include backwater valves. On the City's 2026 fee schedule, a plumbing-only permit is $117 per application.

The City's Residential Protective Plumbing Program lists up to $2,500 for an outdoor storm backwater valve on a home built before January 1, 2004. The City rebates the lesser of the maximum or the cost of the work, the work and the application must be done within 18 months of the permit's issue date, and the City lists the program as currently under review: check ottawa.ca before you rely on it. The rebate is not available for a device the City installed, or for repairing or replacing an existing one.

Because the job digs, the Act requires a locate request first; Ontario Dig Authority asks for it at least 5 business days before you dig, and locates are free. Plumber is a compulsory trade in Ontario, so ask whether a licensed plumber does or signs off the plumbing part.

Before signing, ask each contractor who applies for the permit and who requests the locate, and have both written into the contract.