How to Test for Gas Leaks on a Water Heater at Home
Published: July 21, 2026 — CANRO Heating & Cooling — Greater Vancouver, BC
Soap and Water Test
Mix dish soap with water in a spray bottle. Spray all gas connections: the gas line connection to the gas valve, the gas valve connections to the burner manifold, and the pilot tube connection. Turn the water heater on and watch for bubbles — any expanding bubbles indicate a gas leak.
Other Leak Detection Methods
Electronic gas detectors can detect natural gas at very low concentrations. Listen for a hissing sound near gas connections — this indicates a significant leak. The odour of mercaptan (rotten egg smell) is the most reliable indicator. If you smell gas, do not rely on testing — evacuate and call 911 or the gas utility.
What to Do If You Find a Leak
If you detect a gas leak: turn off the gas supply at the shutoff valve, open windows for ventilation, do not operate any electrical switches, call a licensed gas fitter for repair. If the smell is strong or you cannot locate the shutoff, evacuate the home and call 911 from outside.