How to install a water softener in Quebec?

Installing a water softener in Quebec follows specific rules to protect the potable water network:

Location:

• Install the softener after the water meter and after the expansion tank (if present)
• Often installed in the basement, near the main water entrance, in a drained area
• A bypass valve is mandatory to allow isolating the softener without shutting off water to the whole house

Connection:

• Inlet/outlet: 1 in for standard houses with PEX or copper piping
• Regeneration drain: ½ in pipe directed to a floor drain or standpipe, with an air gap of at least 20 mm
• Prohibition: The regeneration drain must never be directly connected to a sewer pipe (contamination risk)

Benefits:

• Reduces scale in pipes and appliances — scale builds up in the water heater and in appliances
• Reduces the amount of soap and detergent needed for washing

Installation must be carried out by a company holding the RBQ 15.5 contractor licence and by workers holding a CCQ competency certificate: connecting a potable water treatment device to the plumbing system must be done by a person holding a subclass 15.5 (Contractor – Plumbing) licence. The complete price (unit + installation) is not set by any published schedule: it depends on the unit, the diameter and type of the piping, and the drain work. The CMMTQ publishes a reference hourly rate grid (in force on April 26, 2026) for comparing quotes; materials and travel are added on top.