Understanding Cold and Hot Water Supply Systems in Toronto Condos

Cold water is delivered to the buildings by the City of Toronto. If you notice issues with the taste, smell, or colour of cold water affecting all unit taps, contact 311. The condos usually do not alter or filter municipal water. In modern buildings, the hot water is usually centrally heated by the building’s boilers. Both hot and cold water come from the risers to your unit through the two unit’s main shut-off valves. From there, cold and hot water are distributed to all plumbing fixtures inside the unit.

The main shut-off valves mark the boundary between the building’s water supply system (including risers, valves, boilers, etc.) and the unit’s internal plumbing system (including the unit’s main shut-off valves, the unit’s pipes and the unit’s plumbing fixtures themself).

In the majority of condos, the Corporation is responsible for all plumbing on the building side (before the unit’s main shut-off valves), but the unit owners are responsible for all plumbing components on the unit side, including main shut-off valves, the unit’s pipes, cartridges, faucets, and any other plumbing fixtures within the suite (all plumbing fixtures after the unit’s main shut-off valves).

Common Scenarios:

1.         If one fixture in the unit (e.g., a kitchen tap or bathroom faucet) has low pressure or incorrect water temperature, the issue is internal, often caused by a clogged aerator or a worn or blocked cartridge. This must be addressed by the unit owner at their own cost.

2.         Scheduled water shut-offs are a normal part of condominium operations and typically occur 3-5 times per year. After water service is restored, you may occasionally experience issues at one or two plumbing fixtures only, such as reduced pressure or fluctuating temperature. These problems are most often caused by old or worn-out cartridges that fail due to pressure fluctuations inside the pipes during water reactivation. A clogged aerator is another common cause.

These are not system failures—scheduled water shut-offs do not cause damage to fixtures. They only reveal pre-existing wear. If a fixture fails after service is restored, it means its components were already deteriorated and now require attention.

Modern, well-maintained fixtures are designed to tolerate normal pressure variations without issues. If a tap in your unit is not functioning properly after a building water shut-off, this is an in-suite issue and is not related to the building’s plumbing system.

3.         Air bubbles from pressure changes can make water appear cloudy. Pour it into a glass and wait a few minutes—it will clear. This is harmless.

4.         Discoloration or debris at one fixture: This usually indicates a deteriorating faucet or supply hose. Replace the affected parts as needed.

Report to the management immediately if all taps in your unit have no hot or cold water, or water pressure is low throughout your entire unit. The management is to arrange the investigation and repairs.

For the repairs that fall under the owner’s responsibility, you may contact your building's

preferred plumbers or any other licensed and insured contractor of your choice.