How a test is done
- We confirm with staff that the water can be off for the test window.
- We flush each test cock, then hook up the differential gauge.
- Each check valve is tested for tightness and the relief valve for its opening point.
- Shut-off valves on the assembly are checked for a tight close.
- Results are written up; a failed assembly gets a rebuild quote on the spot.
Where backflow devices sit
- On the water entry of plazas, offices and industrial units
- Ahead of boiler make-up water and closed heating loops
- On lawn irrigation tied into the domestic supply
- On carbonators, coffee machines and dish chemicals in kitchens
- Ahead of dental chairs, labs and car-wash equipment
Durham Region enforces cross-connection control through its water supply by-law.
Why a device fails
- Scale and debris lodged under a check disc
- Rubber seats hardened or torn after years of service
- Relief valves that spit from a pressure spike in the street main
- Assemblies installed in a pit that floods or freezes
Regional requirements
Durham Region enforces cross-connection control through its water supply by-law. Premises with a backflow preventer are generally expected to have it tested when installed and on a yearly cycle by a qualified tester, with results submitted to the Region. The details, forms and deadlines can change, so confirm the current requirements with the Region before your due date; we will tell you what we file and when.
New installs and replacements
When a tenant fit-out adds a boiler, an irrigation system or a chemical feed, the hazard level of the site can change and a different assembly type may be required. We size the device to the line, set it where it can be tested and drained, and leave room for the test kit. Older assemblies with no parts available are often cheaper to replace than to rebuild every year.
See the main commercial plumbing page for the other building work we handle.
Questions callers ask
How much downtime does a backflow test cause?
Most single assemblies take less than sixty minutes, and that line is dry only while the gauge is on.
What happens if the device fails?
You hear which seat or spring let go, get a price to rebuild or swap the assembly, and we retest once it is fixed so a pass goes on file.