Water Heater Gas Control Settings — A, B, C Explained
Published: July 21, 2026 — BC Wide Home Services Ltd, doing business as BC Wide Heating & Air Conditioning — Greater Vancouver, BC
What the Letters Mean
Most gas water heater control valves use A, B, C settings or numbers 1-5 to indicate temperature ranges. A or 1: lowest temperature (approximately 32°C/90°F). B or 3: medium (approximately 49°C/120°F) — the recommended setting for most households. C or 5: hottest (approximately 60°C/140°F).
Choosing the Right Setting
For most Vancouver homes, set to B (120°F/49°C). This is hot enough for comfortable showers and effective cleaning while preventing scalding — water at 60°C can cause third-degree burns in 5 seconds. Lower the setting if you have young children or elderly household members. Raise it only if your dishwasher does not have a built-in heater.
Energy impact
Each 10°F reduction in water temperature saves 3-5% on water heating energy costs. Reducing from C (140°F) to B (120°F) saves approximately 6-10% annually — about $20-40/year for a typical household. This small adjustment pays back immediately with no cost.