How Altitude Affects Gas Water Heater Performance in BC

Published: July 20, 2026 — CANRO Heating & Cooling — Greater Vancouver, BC

Altitude Effect

At higher elevations, the air is thinner with less oxygen. Gas burners need less gas flow to maintain the correct air-to-fuel ratio. Without altitude adjustment, the burner would overfire (too much gas for available oxygen), producing soot and carbon monoxide.

When Adjustment Is Needed

Altitude compensation is typically required above 2,000 feet (610 meters). Most Vancouver-area homes are near sea level and do not need adjustment. However, homes in the North Shore mountains, Fraser Valley foothills, or mountain resort communities may need altitude-adjusted equipment.

How It Is Done

Some gas valves have an altitude adjustment screw. Others require a different orifice size. The manufacturer specifications dictate the required adjustment. A licensed gas fitter measures combustion oxygen and adjusts the gas pressure accordingly. Never operate a gas water heater at altitude without proper adjustment.

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Safety Reminder

If you smell gas, suspect carbon monoxide or believe there is an immediate danger, leave the property and contact emergency services or the appropriate gas emergency authority. Do not remain inside — exit the building immediately and call for help from outside.