Backflow prevention keeps contaminated water from siphoning back into the drinking water supply. A backflow preventer is a mechanical assembly fitted on a water line, typically where a property connects to the municipal main, or on irrigation lines, fire sprinkler systems, boilers, or process water setups. Toronto Water requires these devices on most commercial, industrial, and multi-residential properties, and on any property with a cross-connection hazard, along with annual testing by a certified tester to confirm the device is still shutting off backflow properly. This page covers 16 businesses in Toronto that handle this work, from initial installation to the yearly certification test and any repairs that come up along the way.
When hiring, confirm the technician holds current backflow prevention assembly tester certification, since an uncertified test won't satisfy the city's reporting requirements and you'll end up paying for a second visit. Ask how the paperwork is handled: a solid contractor files results with Toronto Water or your property manager directly and gives you a copy, rather than leaving that step to you. Get a written quote before the appointment, since cost depends on the number and size of devices and whether any parts need replacing on the spot.
Our scores weigh licensing and certification, response time, pricing transparency, and how customers describe the actual work afterward, so you're comparing more than just a star average. Read how we put that together in our methodology, or browse the full ranked guide to Toronto plumbers for the wider trade.
