For businesses and buildings
Backflow preventer testing and installation
When pressure in the street main falls, a backflow preventer keeps the water already inside your pipes from being drawn back out to the public supply. Many commercial and multi-unit properties in Toronto are required to have one and to have it tested. We test, repair and install them, and prepare the paperwork.
- Annual testing of RP and double check valve assemblies
- Rebuild kits, check springs and relief valves replaced on site
- New installs sized to the hazard and the water service
- Test reports prepared for submission to the city
- Licensed, insured trade work (details confirmed when you call)
- Diagnosis before anything is cut
- Emergency calls taken
- Etobicoke and the west end
At a glance
- Device types
- Reduced pressure principle (RP), double check valve assembly (DCVA), dual check and vacuum breakers
- Typical sites
- Restaurants, medical and dental offices, car washes, plazas, condos, buildings with boilers or irrigation
- City rules
- Toronto’s water supply by-law (Municipal Code Chapter 851) sets backflow requirements; check the current terms with Toronto Water
- Standards
- Selection and installation follow CSA B64 series guidance and the Ontario Building Code
What backflow is and why the city cares
Normally water flows one way: from the city main into your building. A sudden pressure dip in the street, say from a broken main or firefighters opening several hydrants, can suck water in reverse out of your piping. If that piping is connected to a boiler with chemical treatment, a carbonation system, an irrigation line or a dental chair, that water is not something anyone wants in the public supply.
- A backflow preventer is a set of check valves, and in the case of an RP device a relief valve, that physically stop that reverse flow.
Testing: what we actually do
Testing uses a calibrated differential pressure gauge connected to the test cocks on the assembly. We shut the downstream valve, then check that each check valve holds its required pressure difference and that the relief valve on an RP device opens when it should. The whole test usually takes well under an hour per device.
- If a check fails, we can often rebuild it right there with a repair kit: new rubber, new springs, clean seats.
- Then we retest so the report reflects a passing device.
Installing a new device
The right device depends on the hazard behind it. A severe hazard such as a chemical-treated boiler loop usually calls for an RP assembly; lower hazards may allow a double check. RP devices discharge water from the relief port when they work, so they need a drain nearby and must not go in a pit that can flood.
- We look at your water service size, the space available and the drain location before recommending a device, and we arrange the permit where one is required.
Keeping on top of the paperwork
- Keep each device’s make, model, size and serial number on file.
- Note the test due date in your building calendar.
- File every test report with your property records.
- Tell us if tenants add equipment that connects to the water supply.
When to call about backflow
- A letter from the city asking for a test report or survey
- Water spitting from the relief port of an RP device
- A new tenant installing coffee, soda, dental or lab equipment
- Low pressure across the building after a device was added
- No record of when the existing device was last tested
How a backflow test runs
Confirm the shut-down
We agree a short window when water can be off.
Test each check
Gauge on the test cocks, every check and relief valve measured.
Repair if needed
Rebuild kit fitted and the device retested.
Report
Pass or fail figures recorded, ready to file and to send to the city.