Carbon monoxide (CO) is a poisonous gas that you cannot see, smell or taste. It can be produced when a gas appliance is faulty, badly fitted or not burning properly, and with the heating running more as winter sets in, it is worth knowing the signs.
Here is what to look out for, why a CO alarm matters and what to do if you think there is a problem.
Where carbon monoxide comes from
CO is produced when fuel does not burn fully. The NHS lists gas boilers, gas cookers, heaters and fires among the common sources, along with things like portable generators, barbecues and engines running in enclosed spaces.
A gas appliance that is working properly and has a clear flue should not put CO into your home. Problems tend to come from appliances that have not been looked after, flues that are blocked or damaged, or rooms without enough ventilation.
Symptoms of carbon monoxide poisoning
The NHS lists these symptoms:
- Headache
- Dizziness
- Feeling sick or being sick
- Feeling weak
- Tiredness and confusion
- Chest and muscle pain
- Shortness of breath
Because these look a lot like flu or a bad cold, CO poisoning is easy to miss. The NHS points out that symptoms may get worse when you spend time in an affected room or building and get better when you leave or go outside. If that pattern sounds familiar, take it seriously.
Warning signs on gas appliances
As well as symptoms, look out for signs that an appliance is not burning properly:
- Black marks or staining on or around a boiler, fire or heater
- On appliances where you can see the flame, a lazy yellow or orange flame instead of a crisp blue one
- A pilot light that keeps going out
- More condensation than usual in the room with the appliance
If you see any of these, stop using the appliance and have it checked by a Gas Safe registered engineer.
What to do if you suspect carbon monoxide
- Stop using the appliance if you can and turn it off
- Open doors and windows and get everyone outside into fresh air
- Call the National Gas Emergency Service on 0800 111 999. It is free and open 24 hours
- Get medical advice. The NHS says to call NHS 111 if you think you have symptoms, or 999 if someone has trouble breathing, sudden confusion or has lost consciousness
- Do not use the appliance again until a Gas Safe registered engineer has checked it
Fit a carbon monoxide alarm
RoSPA advises having an audible CO alarm in your home, fitted near your gas appliances and positioned following the manufacturer's instructions. They are inexpensive, easy to fit and widely available. Test it regularly and replace it when it reaches the end of its life.
RoSPA also makes the point that an alarm is not a substitute for regular servicing. It warns you when there is already a problem. A yearly service is what stops the problem developing. Our guide on how often a boiler should be serviced explains what a service covers.
Rules for landlords
Since 1 October 2022, landlords in England, both private and social, must fit a carbon monoxide alarm in any room used as living accommodation that contains a fixed combustion appliance, such as a gas boiler. Gas cookers are excluded. Landlords must also repair or replace an alarm once they are told it is faulty.
That sits alongside the yearly gas safety check. See our guide to the landlord gas safety certificate for what that involves.
Keep your appliances safe
Gary carries out boiler servicing and landlord gas safety checks, checking the flue, ventilation and gas pressures properly. He also fits and checks cookers, hobs and other appliances through his gas appliance installation service.
He covers Gloucester, Tewkesbury, Cheltenham and nearby. For a gas emergency, always call 0800 111 999 first. For a service or safety check, call Gary on 07454 117678 or get in touch.