A carbon-monoxide alarm is a backup warning, not a substitute for correct installation, ventilation, maintenance or servicing. Choose an alarm certified for the market, install and maintain it exactly to the manufacturer instructions, and know the emergency response before it sounds.

If an alarm sounds or CO is suspected

Leave the property, warn others and use the official gas/emergency route. Seek medical advice for possible exposure. Do not silence the alarm and re-enter to investigate the boiler yourself.

Buying and positioning

Check the current legal requirements for the property’s nation and tenure. Select a compliant alarm from a reputable source and follow its instructions for room, distance, height, obstructions and unsuitable locations. Generic placement graphics cannot override a model’s instructions.

Record model, standard marking, installation date, replace-by date, battery type and test method. Avoid buying an untraceable alarm solely on price.

Testing and maintenance

Use the test button and schedule stated by the manufacturer. Testing the electronics does not prove the room is CO-free or the boiler safe. Replace batteries or the unit when instructed and keep vents clear.

Appliance safety

Have gas work performed by a Gas Safe registered engineer in Great Britain or an RGI in Ireland. Keep boiler service and landlord safety records as applicable. Never block ventilation or alter a flue.

Frequently asked questions

Does an alarm replace a boiler service?

No. It warns of detected CO under its design conditions; it does not inspect, maintain or certify the appliance.

Where should positioning instructions come from?

The alarm manufacturer’s current manual, read alongside current rules for the nation and property type.

Suggested on-page component

Use a CO Alarm Record and Replacement Planner with manufacturer-link, test and replace-by fields. It must open with emergency guidance and never claim to verify safety.

Related guides

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