Gas Plumbing Safety Inspection Checklist — Protect Your Home

Your main gas shutoff is typically at the meter (outside) or where the gas line enters the building. Verify you can reach it, identify it, and know which direction closes it (quarter-turn valves: perpendicular to pipe = off). Do NOT actually turn it off for testing — relighting pilots and purging air from lines requires a professional. Just confirm access and operation direction. Label it clearly if it isn't already.

Every gas appliance should have its own shutoff valve within 6 feet of the appliance. Check: water heater, furnace, stove/range, dryer, fireplace. If any appliance lacks a dedicated shutoff, or if the valve is buried behind stored items or sealed behind drywall, schedule a gas plumber to add one. In an emergency, you need to isolate a single appliance without shutting gas to the entire home.

Walk your accessible gas lines (basement, crawlspace, utility areas). Black iron gas pipe should show no rust-through, pitting, or flaking. Pipe should be supported every 6–8 feet and not resting on or touching anything that could cause abrasion. CSST (corrugated stainless steel tubing — yellow jacket) must be properly bonded to the home's grounding system. Any pipe showing damage warrants a professional evaluation — do not attempt repair yourself.

Flexible connectors (the corrugated lines connecting appliances to the gas stub-out) have a 10–15 year life. Older uncoated brass connectors (pre-2000) are recalled due to cracking risk and should be replaced immediately. Modern stainless steel connectors with yellow coating are the standard. Check for kinks, stretching, or signs of being reused (connectors are single-use — never reuse a connector that's been disconnected). Replace any connector older than 15 years proactively.

Mix dish soap and water in a spray bottle (50/50). Spray every accessible threaded connection, union, valve stem, and flexible connector fitting. Watch for bubbles forming — any bubble growth indicates a gas leak at that joint. Even tiny bubbles mean gas is escaping. Mark the location, ventilate the area, and call a licensed gas plumber for repair. Do not use matches or lighters to check for leaks under any circumstances.

The vent pipe (B-vent or PVC, depending on appliance type) must be continuously connected from the appliance draft hood to the roof penetration with no gaps, separated joints, or missing screws. A single disconnected joint in a basement vent pipe sends 100% of combustion products (including CO) into the home. Visually trace each vent run from appliance to roof. Secure any joints with 3 sheet metal screws minimum per joint.

Natural-draft appliances (most tank water heaters, older furnaces) depend on hot exhaust gases rising naturally through the vent pipe. Any downward dip or sag creates a trap where gases pool and can backdraft into the home. Sight along each horizontal vent run — it must slope consistently upward toward the chimney or roof exit. Sagging vent pipes need additional support hangers.

Gas appliances consume oxygen during combustion. An enclosed mechanical room without adequate air supply creates negative pressure that pulls exhaust gases backward through vent pipes (backdrafting). Check that combustion air openings (louvered doors, duct openings to outside) are not blocked by stored items, insulation, or sealed off during renovations. A fully enclosed, sealed mechanical room is a carbon monoxide hazard.

Turn on the water heater and wait 5 minutes for the vent to warm. Hold a lit match or incense stick near the draft hood opening — smoke should be drawn UP into the vent. If smoke blows outward or hangs in the air, the appliance is backdrafting. Common causes: bathroom exhaust fans creating negative pressure, blocked vent pipe, improper vent sizing. Backdrafting is an immediate carbon monoxide risk — resolve before continuing to use the appliance.

Press the test button on every CO detector in the home. Detectors should be on every level, within 15 feet of sleeping areas, and near (but not inside) rooms with gas appliances. CO detectors have a 5–7 year lifespan — check the manufacture date on the back and replace any unit over 5 years old. A detector that beeps during testing may still have a dead sensor — if it's more than 5 years old, replace it regardless of test results.

Your gas meter is the utility's responsibility to maintain, but damage from vehicles, landscaping, or settling affects your safety. Check that the meter isn't leaning, the riser pipe isn't stressed, and no vegetation or structures block access. The utility needs immediate access to your meter in an emergency — maintain 3 feet of clearance on all sides. Report any damage or odor near the meter to your gas utility, not a private plumber.

Every person in the home should know: what natural gas smells like (rotten eggs/sulfur), how to leave the building without operating electrical switches or creating sparks, where to go (upwind, at least 100 feet away), and who to call (gas utility emergency line, then 911 — not a plumber). Post the gas company emergency number on the refrigerator and in the garage near the meter. Do NOT try to find or fix a gas leak yourself.