What do I do if I smell gas?

Strong smell: leave without operating switches, phones, or anything that sparks, and call the utility's emergency line from outside; they respond free and fast. Faint, localized smell at an appliance: ventilate, don't spark, and check fittings with soap solution or leave it to the utility, who would rather come than not.

How do I check a gas fitting for leaks?

Brush or spray a soapy water solution on the joints and watch for growing bubbles with the gas on. Bubbles mean a leak: snug the fitting and retest, and call a professional for anything that keeps bubbling. Never search with a flame.

How often should gas connectors be replaced?

Whenever the appliance moves or is replaced is the working rule, connectors are not reused, and any uncoated brass connector from decades past is replaced on sight due to a documented failure history.

Can I install my own gas appliance connector?

Jurisdictions vary and so should confidence: the flexible connector with its factory-flared ends is designed for accessible hookups, but gas work rewards professionals, and the soap test plus a utility or plumber check is cheap against the alternative.

Gas Appliance Connections: The Leak Check

Page last reviewed: August 2026 · Reviewed by Harold R. Bennett, retired home inspector

Natural gas and propane are odorless by nature and famous-smelling by law: the rotten-egg odorant (mercaptan) is added precisely so noses become leak detectors, and the household gas-safety program is mostly knowing what to do with what the nose reports. A gas appliance leak check is the soap-bubble ritual at fittings plus a short set of connector rules, and the escalation ladder above it is short and absolute. This reference covers the responses by smell strength, the test, the connector rules, and the division of labor with the utility.

The smell ladder

Strong or widespread gas smell, hissing, or a known line strike: out, now, everyone, operating nothing on the way, no light switches, no phones until outside, no garage door opener, since the hazard at that concentration is ignition by any spark, and the call is the utility’s 24-hour emergency line (or 911) from outside; gas utilities respond to odor calls free, fast, and by explicit preference, their standing message being call for any smell, however small the caller feels. Faint, localized smell at one appliance, the whiff at the range’s connection, the trace near the water heater, permits the measured response: ventilate the area, spark nothing, and either soap-test the fittings below or make the same utility call, which remains the right answer for anyone uncertain. Trace odors with innocent explanations exist, a range burner that caught slowly, a pilot relight, an empty trap letting sewer gas impersonate (a different rotten smell with its own diagnostic), but the tie always breaks toward the call. Methane detectors, wall-plug units distinct from CO alarms (which do not detect gas leaks, a point worth stating), add an instrument where noses sleep or fade.

The soap-bubble test

The classic leak check finds what noses localize: a solution of dish soap and water (or commercial leak-detect fluid), brushed or sprayed generously on every joint in question, valve connections, flare nuts at the connector’s ends, unions, the sediment-trap tee, with the gas on, and watched a full minute. Growing bubbles mark the leak, foam clusters and rafts at a specific joint, distinct from the solution’s own suds sliding off. The response ladder at a bubbling joint: snug the fitting modestly (flare fittings want firm, not heroic, torque, and over-tightening splits them) and retest; a joint that keeps bubbling, or any leak at the appliance’s internal valves and manifolds, ends the amateur portion and calls the plumber or utility. The forbidden method earns its sentence every year in burn statistics: never search for a gas leak with a flame.

The connector rules

The flexible corrugated connector between the wall’s shutoff and the appliance carries most of the residential risk history, and its rules are short. Never reused: connectors are replaced, not transferred, whenever an appliance moves or changes, the flare ends work-hardening and the tubing fatiguing with handling. Never through walls or floors: connectors serve the accessible last few feet only, with rigid pipe doing the concealed work. Never kinked, coiled tight, or strained: the range shoved back onto its own connector is the gas version of the dryer’s crushed duct. The old-brass replacement rule: uncoated brass connectors from roughly the 1960s and 70s have a documented, CPSC-publicized failure history (the ends separating), and any found in service, behind old ranges and dryers, replace on sight, unmoved and undisturbed until the swap, since handling is what breaks them. Each appliance also owes an accessible shutoff valve at its connection, the range’s behind-the-drawer valve and the dryer’s behind-the-machine one being the map every household adult should know alongside the main water shutoff, plus the meter’s street-side wrench valve for the whole house, closed only for cause and relit by the utility.

The division of labor

The utility owns the emergency response, odor calls, meter and street-side issues, and will check appliance-side suspicions gladly; plumbers and gas-licensed technicians own the repairs, new runs, and installations, with permits where jurisdictions require them; and the homeowner owns the nose, the soap bottle, the connector rules, and the annual glance that pairs naturally with the combustion-safety inspection round: connections unstrained, valves reachable, sediment traps present, and nothing flammable stored against the appliances that make flames for a living.

The bottom line

The smell is the system working: strong means out and call from outside, faint means ventilate, soap the joints, and still call when unsure. Bubbles name the leak, flares want snug not heroic, connectors never move houses or thread walls, and old bare-brass ones retire on sight. The utility would always rather come than not, which is the one fact that makes every other decision easy.