Know Your Three Shut-Offs Before You Need Them
Every gas-fired heating or hot-water appliance has up to three things you may need to turn off in an emergency: water, electrical power, and gas. Finding them now — on a calm afternoon — means you will not be hunting for valves while water spreads across the floor.
Walk to your mechanical room and identify each one. Most Greater Vancouver homes keep the boiler, furnace, and water heater within a few feet of one another, so the same trip covers all three. Snap a photo on your phone and label it so any household member can act.
Shutting Off the Water Supply
Tank water heater: Look for the cold-water inlet valve on top of the tank. If it is a round handle, turn it fully clockwise; if it is a lever, turn it a quarter turn so it sits across the pipe.
Boiler or hydronic system: Find the cold-water make-up line feeding the boiler and close its valve. This stops the system from drawing in fresh water to replace what is leaking.
Tankless water heater: Close the cold-water isolation valve on the inlet side, usually one of the service valves directly beneath the unit.
If you cannot find the local valve, go to the home's main water shut-off. In most BC houses it is near the front foundation wall, in the basement or crawlspace where the municipal line enters, or at the water meter. Turning it off stops water to the whole house, which is fine in an emergency.
Cutting the Electrical Power
Electricity near standing water is a shock hazard, so shut it off before you do much cleanup.
Many BC furnaces and boilers have a dedicated power switch right beside the unit — it often looks like an ordinary light switch mounted in a metal box on or near the appliance. Flip it off. If there is no local switch, go to your main electrical panel and turn off the breaker labelled for the furnace, boiler, or water heater.
Important safety rule: never reach for a switch or breaker while standing in water or with wet hands. If the floor around the panel is already wet, stop and call an electrician or call us at 604-359-1081 for guidance.
Turning Off the Gas (and When Not To)
Each gas appliance has a manual shut-off valve on the gas line close to the unit. The handle runs in line with the pipe when open; give it a quarter turn so it sits crosswise and the gas is off.
You do not normally need to touch the gas for a simple water leak. Reserve the gas shut-off for situations where you smell gas, suspect a combustion problem, or a technician has asked you to.
If you ever smell gas — that distinctive rotten-egg odour — do not search for the valve and do not flip any switches. Get everyone out of the home, then call FortisBC at 1-800-663-9911 or 911 from outside, and call us at 604-359-1081 afterward. Safety first, always.
After Everything Is Off
With water, power, and (if needed) gas isolated, the leak should stop getting worse. Mop up standing water, lift belongings off the floor, and ventilate the room.
Do not turn the appliance back on to test it. A boiler or water heater that has lost water can be damaged by firing dry, and restarting may hide the very symptom a technician needs to see.
Call GasBoilers.ca at 604-359-1081. Tell us which appliance leaked, what you shut off, and what the leak looked like. Our parent company CanroHeat services boilers, furnaces, heat pumps, and water heaters across Greater Vancouver, and we will arrange a proper repair before you restore heat or hot water.