A suspected gas escape or carbon monoxide incident is an emergency, not a routine repair ticket. Do not delay action while waiting for the usual contractor.
Respond immediately
- Treat a gas smell, suspected escape or CO alarm as requiring urgent professional advice.
- Keep occupants out of danger and avoid actions that could ignite gas. Do not operate electrical switches in a suspected gas atmosphere.
- Seek urgent medical help if exposure or illness is suspected, and tell responders about the possible carbon monoxide incident.
Coordinate professional attendance
- Contact the gas emergency service rather than relying only on a voicemail to a maintenance contractor.
- Give the address, symptoms or alarm information and any known appliance details.
- Ensure responders can gain access safely and follow their restrictions on the supply and appliances.
Manage the aftermath
- Arrange the appropriate qualified engineer for investigation and repair.
- Provide suitable interim heating or other arrangements if services remain isolated.
- Retain the incident and repair evidence and confirm what can safely be used before telling the household normal service is restored.
Example: the alarm stops sounding
A fictional CO alarm becomes silent after occupants leave the room. Do not assume the danger has passed or remove the alarm battery. Follow emergency advice and have the cause investigated before the appliance is used again.
What to do
- Move away from the danger and call the National Gas Emergency Service on 0800 111 999 from a safe place.
- Call 999 for immediate danger or a medical emergency.
- Follow emergency instructions and use a suitably qualified Gas Safe engineer before reuse.
Evidence to keep
- Report time, emergency reference and attendance records.
- Isolation, engineer findings, repair and confirmation before recommissioning.
Sources and guidance
- Domestic gas safety: emergencies and common questionsHealth and Safety Executive · checked 20 October 2026
- Gas safety: landlords and letting agentsHealth and Safety Executive · checked 20 October 2026