The response sequence for a suspected gas escape or carbon monoxide, and where a non-Gas-Safe-registered plumber's role ends.
Treat a suspected gas escape or carbon-monoxide exposure as an immediate safety concern, including when it is discovered during unrelated plumbing work.
People and emergency help first
Get people into fresh air without delaying to investigate the appliance. Avoid flames, smoking and electrical switches near a suspected gas escape. In Great Britain, call 0800 111 999 from a safe place for a suspected mains-gas emergency. For an LPG escape, contact the LPG supplier’s emergency service from safety; call 999 for fire or immediate danger. Do not handle leaking cylinders or search for a leak beside them.
Ventilate through an accessible door or window, or close a safely reachable gas emergency control, only if that does not delay escape or require entering danger. Keep a suspect appliance unused until the appropriately qualified engineer has investigated and made it safe.
Recognise possible carbon monoxide
CO has no smell, colour or taste. Symptoms can include headache, dizziness and nausea; illness affecting several occupants or improving away from the building is a warning sign. Soot or yellow-brown staining and an abnormal lazy yellow flame on a burner intended to burn blue also warrant action. Some decorative fuel-effect appliances are designed to burn with yellow flames, so flame colour alone does not prove a fault.
Treat a sounding CO alarm as real. Do not wait for an alarm when symptoms or other evidence already suggest exposure. Leave the building and get medical help. After suspected exposure, call 999 for weakness, chest or muscle pain, breathing difficulty, sudden confusion or unconsciousness. Contact NHS 111 urgently for other possible symptoms; an affected person must not drive. Do not return until advised. A gas-appliance concern also needs emergency reporting from safety.
Respect the gas-work boundary
Gas work needs competence for the actual task. Business work on domestic gas fittings also needs the appropriate Gas Safe registration, apart from the law’s limited exceptions. Do not disturb gas-carrying parts, combustion controls or a combustion-chamber seal without that competence and registration. Customer consent and a promise of a later sign-off do not authorise unregistered gas work.
Tasks explicitly intended for the user, and separate non-gas water or electrical work, have different limits. They must remain within actual competence and the appliance instructions, without affecting gas safety or combustion. If you are unsure where the boundary is, refer the task. None of this permits continuing routine work while people remain exposed to a suspected gas or CO hazard.
Help after loss of heating
A dangerous appliance stays out of use even when the customer needs warmth. For a vulnerable occupant in cold weather, help arrange prompt repair and suitable temporary warmth. Portable electric heaters need safe placement and an appropriate electrical supply; warm clothing and support from carers or other services may also help. Never recommend a gas oven or hob as a room heater.