Emergency Advice
Heating & Gas Emergencies: What To Do Right Now
Reviewed by our Gas Safe registered engineers · Last updated 22 July 2026
Most heating faults can wait for a booked appointment. A small number genuinely can’t, and knowing the difference in the first minute matters more than anything else on this page. If you’re here because something feels seriously wrong right now, start with the gas-emergency section below before reading anything else.
Quick answer: if you smell gas or suspect carbon monoxide, leave the property, don’t operate any switches, and call the National Gas Emergency Service on 0800 111 999 from outside. For anything else urgent but not gas-related, call us directly.
Is This A Gas Emergency?
If you smell gas or suspect carbon monoxide
1. Leave the property and take everyone, including pets, with you.
2. Don’t operate any switches — lights, doorbells or anything electrical, including your phone, while still inside. A spark near a gas leak is a real risk.
3. Don’t light anything or smoke near the property.
4. Call the National Gas Emergency Service on 0800 111 999 once you’re safely outside. This line is free, available 24/7, and is the correct first call for a suspected gas leak — not us directly, as they can isolate the supply.
5. If you have symptoms of carbon monoxide poisoning — headache, dizziness, nausea, breathlessness, particularly if several people or pets are affected at once — treat it as a medical emergency and seek medical help as well.
Other Emergencies
Other situations that need urgent attention
Burst Pipe
Isolate at the main stopcock immediately, then call us. Every minute matters for water damage.
No Heat In Freezing Weather
Especially urgent with young children, elderly residents, or anyone vulnerable in the property.
Loud Banging Or Burning Smell
Turn the boiler off at the isolation switch and call us — don't try to reset it repeatedly.
Carbon Monoxide
What every household should know about CO
Carbon monoxide has no smell, no colour and no taste, which is exactly why a working CO alarm matters more than people realise. It’s produced when gas doesn’t burn completely — often from a blocked flue, poor ventilation, or a fault inside the appliance. Symptoms (headache, dizziness, nausea, tiredness) are easy to mistake for a virus, and are often worse when several household members or pets are affected around the same time, or ease as soon as you leave the property. A CO alarm should be fitted near any gas appliance and tested regularly — it’s one of the cheapest pieces of safety equipment you can own relative to what it protects against.
Common Mistakes
Where people get the response wrong
- Trying to locate a gas leak yourself by sniffing around pipework, rather than leaving immediately and calling it in.
- Flicking a light switch on the way out of a property where gas is suspected.
- Ignoring a CO alarm that's gone off once, assuming it's a false alarm or low battery without checking.
- Repeatedly resetting a boiler that's making unusual noises or smells, rather than turning it off and calling for help.
FAQs
Emergencies — your questions answered
What's the difference between a gas emergency and a boiler breakdown?
A boiler breakdown means the boiler has stopped working — inconvenient but not dangerous. A gas emergency involves an actual or suspected gas leak, a safety risk requiring you to leave the property and call the National Gas Emergency Service, not just book a repair.
Can I turn my gas supply back on myself after an emergency shutoff?
No — once the National Gas Emergency Service has isolated your supply, it needs to be checked and safely reconnected by a Gas Safe registered engineer, not turned back on independently.
Is it safe to stay in the property if a CO alarm has gone off but then stops?
Treat any CO alarm activation as genuine until proven otherwise. Leave the property, ventilate if safe to do so from outside, and have the cause investigated before assuming it was a false alarm.
What should I do if I can smell gas but I'm not sure it's from my property?
Call the National Gas Emergency Service on 0800 111 999 regardless — they can help identify the source and it costs nothing to check, whether the leak turns out to be yours or a neighbouring property.
Is a burst pipe always an emergency, or can some wait?
A pipe actively spraying or flooding is always urgent — isolate and call immediately. A small, contained leak that you’ve successfully isolated can often wait for a normally booked visit rather than an emergency callout.
Do I need to evacuate pets as well as people if I suspect a gas leak?
Yes — pets are just as vulnerable to gas and carbon monoxide exposure as people, so they should leave the property along with everyone else.
How do I know if my heating loss counts as an emergency or just an inconvenience?
Cold weather with vulnerable residents (children, elderly, anyone with health conditions) pushes it into emergency territory. Mild weather with otherwise healthy adults can usually wait for the next available appointment.
What information should I have ready when I call in an emergency?
Your address, what you can see or smell, whether anyone’s shown symptoms, and whether you’ve already isolated gas or water. Having this ready speeds up the response considerably.
Can carbon monoxide poisoning have long-term effects even after a mild exposure?
Even relatively mild exposure can cause lingering symptoms in some people, so any suspected exposure is worth mentioning to a doctor rather than assuming it’s fully resolved once you feel better.
Will the Gas Emergency Service charge me if it turns out to be a false alarm?
No — calling the National Gas Emergency Service to investigate a suspected leak is free regardless of the outcome. Never hesitate to call because you’re worried about being wrong; treating a suspected leak seriously costs nothing and is exactly what the service exists for.
After a gas shutoff, how long before an engineer can reconnect the supply?
It depends on engineer availability and what caused the shutoff, so we can’t give a single fixed timeframe, but we treat post-emergency reconnections as a priority and will give you an honest estimate when you call. In the meantime the property is safe with the supply isolated — the priority is a proper check before reconnection, not rushing.
Related
Related emergency guides
What to do when the boiler fails.
Read guideEmergencyCarbon Monoxide Warning SignsThe symptoms and what they mean.
Read guideEmergencyI Can Smell GasThe exact steps, in order.
Read guideLeaksLeaksBurst pipes and water emergencies.
Read guidesHeatingNo Heating In WinterWhen losing heat is urgent.
Read guideBoiler ProblemsBoiler ProblemsNon-urgent boiler faults.
Read guidesFor non-gas emergencies, call us directly. We attend genuine emergencies across Haringey, Hornsey and Barnet, plus the rest of our coverage area.
Genuine emergency, not gas-related?
Call us directly — we prioritise urgent no-heat and flooding callouts across North London. (For a suspected gas leak, call the National Gas Emergency Service on 0800 111 999 first.)
Gas Safe Registered 918817 | North London specialists | 24/7 emergency cover