Carbon monoxide alarm sounding: exactly what to do, in order
Carbon monoxide is colourless, odourless and can be fatal. If your alarm sounds, treat it as real every single time, even if nobody feels unwell.
Where a sounding CO alarm usually comes from
Stop using all fuel-burning appliances, open doors and windows, leave the property, and call the National Gas Emergency Service on 0800 111 999 for gas. For oil appliances, ventilate, leave and call an OFTEC engineer once outside. Seek medical advice if anyone has headaches, nausea, dizziness or confusion, and tell the clinician you suspect CO. Do not restart the appliance until it has been tested.
Published business details
- Based at 24 Bristol Road, Radstock, BA3 3EE
- Telephone enquiries: 07516 118198
- Opening hours: Monday to Friday, 8:30am to 5:00pm
Things worth knowing about a sounding CO alarm
- 0800 111 999 is the free national gas emergency number
- Do not go back inside to investigate the appliance
- Symptoms that improve when you leave the house are a red flag
- Alarms must meet BS EN 50291 and be within their expiry date
- Both gas and oil appliances can produce carbon monoxide
Questions we get asked
- What if the alarm stops when I ventilate?
- It still needs investigating. Ventilation clears the gas but not the fault that produced it.
- How often should alarms be replaced?
- Check the printed expiry date — most sensors are rated for seven to ten years.
Related help pages
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- Worcester rangeWorcester Greenstar CDi Classic: the regular boiler option
- Boulter rangeBoulter oil boilers: servicing a legacy brand still in use
Services that cover this
Where we deal with this
Get a sounding CO alarm looked at properly
In practice: Never wait and see with CO. Ventilate, evacuate, call the emergency line, and only restart after an engineer has tested the appliance.
Use the enquiry form to describe the appliance, fault code and what changed before the problem started.
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