I can smell gas at the barbecue

Each cause below lists the signs that point at it rather than at the others. Start with the signs, not with the fix.

1. A hose, regulator or connection is loose, cracked or perished.

   common

   Signs it is this one

   • The smell is strongest at the cylinder, regulator or hose rather than at the burners.
   • The hose is visibly cracked or hardened, or the regulator is past its service life or shows corrosion or water damage.
   • The smell is present with the burners unlit and the cylinder valve open.

   Why it happens: Rubber hoses harden and crack with age and UV exposure, and connections loosen with handling and transport. These are the commonest points of failure on a domestic gas barbecue. Liquid Gas UK treats a regulator as a wear item with a finite life: the manufacturer's stated service life governs, ten years applies where none is stated, and any sign of wear, leakage or damage means replacement whatever its age.

   What to do

   • With the barbecue outdoors, the burner controls off and the gas on but nothing lit, brush a solution of roughly one part washing-up liquid to four parts water onto the connections. Bubbles forming or growing show escaping gas. Never use a flame to look for a leak. — after cook, reliable

     Rinse the connections with water afterwards, as the solution can be mildly corrosive.

   • If a connection still leaks after the fitting has been remade, turn the gas off and stop using the barbecue. Replace hoses and regulators rather than repairing, adjusting or forcing them, and never fit a second-hand regulator. — after cook, reliable

     This is where the published guidance stops and so does BBQHQ. Weber's manual sends the reader to customer service at this point; Liquid Gas UK forbids tampering with or adjusting a regulator unless qualified. If you are not confident, have it checked.

   Next time

   • Check the hose for cracking at the start of every season and replace it on the manufacturer's schedule.
   • Replace the regulator on its stated service life, or after ten years if none is stated, and sooner on any sign of wear, leakage or damage.
   • Leak-check every time a fitting is disconnected and reconnected, not only when something smells wrong.

2. A control knob was left open with the burner unlit.

   occasional

   Signs it is this one

   • The smell is strongest at the burners or inside the hood.
   • A control knob is not in the off position, or an ignition attempt failed a moment ago.
   • A burner was alight and has gone out during the cook.

   Why it happens: Unburnt gas accumulates, particularly under a closed hood, where it can collect in a quantity that ignites violently when lit. Weber's instruction for a burner that goes out mid-cook treats this as the live hazard: the gas valve is shut, the lid opened, and a fixed interval allowed to pass before any attempt to relight.

   What to do

   • Turn every control off, open the lid, and wait five minutes before any further attempt to light it. — during cook, reliable

     Five minutes is Weber's own figure for relighting after a burner goes out, not an estimate.

   Next time

   • Light the burner before opening the gas fully, and close the cylinder valve first when shutting down.

3. An insect nest in the burner venturi is forcing gas back out of the air opening — a smell of gas that is not a leak.

   occasional

   Signs it is this one

   • The burners are alight and burning yellow and lazy rather than blue at the same time as the smell.
   • A soapy-water test on the cylinder, regulator and hose connections finds nothing.
   • The barbecue has been stored or unused for a season.

   Why it happens: Spiders nest in the venturi section of burner tubes, which is why manufacturers fit screens over the combustion air openings. Weber states that a nest obstructs normal gas flow and can cause gas to flow back out of the air opening, so gas escapes from the appliance while every joint is sound. The named consequence is a fire in and around the gas valve.

   What to do

   • Turn the gas off and stop cooking. The spider and insect screens need inspecting and cleaning before the barbecue is lit again, following the manufacturer's procedure with the cylinder disconnected. — during cook, reliable

     Weber's instruction where a screen is damaged or cannot be cleaned is to contact customer service rather than run the appliance without one.

   Next time

   • Inspect the spider and insect screens at least annually and specifically after a period of storage or non-use.