Water-Main Shut-Offs and Valve Replacement

Most of the seized valves we replace are multi-turn gate valves. Inside one is a brass wedge on a threaded stem. The stem corrodes and binds, the packing around it dries out and weeps, and the wedge can corrode through and drop off the stem, so the handle turns freely while the water keeps running. Others close most of the way and refuse to seal, which is worse than useless mid-repair.

Forcing a seized gate valve is a bad idea. The handle or stem snaps, the water can no longer be shut off at all, and a scheduled job becomes an urgent one. If yours will not move under reasonable hand pressure, leave it alone and have it replaced.

The replacement is a full-port ball valve. Quarter turn, no packing to dry out, nothing to corrode off a stem, and it either shuts or it does not. Full-port matters because a reduced-bore valve throttles flow to the whole building. Where there is room we fit a second valve downstream, so future work does not depend on one valve.

The reason a leaking kitchen faucet means no water anywhere is that nothing is isolated. Plenty of older houses were built with a main valve and nothing else. Every toilet, sink, appliance and hose bib should have a stop of its own, and a multi-unit or commercial building needs a way to isolate a floor or suite without cutting off everyone else.

The stops themselves need attention. Multi-turn angle stops with a rubber washer seize over the years, then leak from the packing nut when somebody finally cranks them. Quarter-turn stops are the sensible replacement. On appliances the connection matters more than people think: laundry boxes, dishwasher and fridge lines and boiler fill lines deserve a proper valve rather than a self-piercing saddle fitting, which is a leak waiting for a date.

Fast-closing solenoid valves in washing machines and dishwashers are the usual source of water hammer, the bang you hear when an appliance shuts off. That shock loads every joint on the line. An arrestor near the appliance and properly secured pipe runs deal with it, before it works a fitting loose somewhere you cannot see.

Outside taps take the most damage in a Toronto winter. A frost-free sillcock puts the valve seat well back inside the heated wall and lets the outside section drain, provided it was pitched slightly downward and the hose comes off in the fall. Leave the hose connected and the frost-free design does nothing, because the water cannot get out. Better again is a frost-free bib plus an interior shut-off with a bleeder cap, so the outside line gets closed and drained every autumn.

Past the wall of the building is the curb stop, the municipal valve on the service line, usually under a small round cover in the boulevard or the front lawn. That valve is city infrastructure. It is not the property owner's to operate, the box is often full of soil or paved over, and working at it with a homemade key ends in damage the owner pays for.

When there is no working valve inside the building, the service has to be shut at the curb before anything can be replaced, and that is arranged through the municipality. We put in the request, work within the window the city gives us, and have the new valve ready so the water is off as briefly as possible. One more argument for replacing a questionable main valve while it is still your choice.