Carbon Monoxide Alarms: Beyond the Service – Your Critical Winter Safety Shield. November 01, 2025 Carbon Monoxide Alarms: Beyond the Service – Your Critical Winter Safety Shield.The Silent Killer: Why Your CO Alarm is as Crucial as Your Boiler Service This Winter (Horsham & Adur Safety Guide)The arrival of the colder months means your gas boiler in Horsham or Adur will be working harder than at any other time of the year. While we at Prime Boiler Care stress the importance of an annual boiler service, the latest Registered Gas Engineer magazine (Issue 188) highlighted a safety component that requires your immediate attention: The Carbon Monoxide (CO) alarm.This device is your critical line of defence against a gas leak you cannot see, smell, or taste. Here is an in-depth look at what the magazine emphasised and what you need to know now.Understanding the 'Mandatory' Role of the CO Alarm.The industry magazine detailed the evolving legal and best practice standards around CO alarm installation. The key takeaway is that these alarms are now considered a mandatory safety device when a combustion appliance is present, rather than an optional extra.For homeowners and landlords in the Horsham District and Adur District, the standard is clear: an alarm should be correctly installed in the same room as the gas appliance (boiler, gas fire, or cooker) and in accordance with the manufacturer's instructions and building regulations. Landlords have a legal duty to ensure a working CO alarm is fitted in rooms with a fixed combustion appliance. Prime Boiler Care is meticulous in checking this during our Landlord Gas Safety Records.The Protocol: What Happens When an Alarm Activates?The magazine reviewed the strict procedures followed by engineers and Gas Distribution Networks when a CO alarm sounds. This is an example of the industry’s high-level readiness to protect the public.If your CO alarm goes off, you must leave the property immediately and call the National Gas Emergency Service. Do not turn off the boiler or try to ventilate the property first. A qualified and registered engineer will be dispatched to investigate the source of the CO leak. We follow the Gas Industry Unsafe Situations Procedure, ensuring the appliance is made immediately safe, decommissioned, and locked off if necessary, to prevent its use until repaired.Prime Boiler Care's Recommendation: Check the Life of Your AlarmCO alarms do not last forever. They contain sensors with a limited lifespan, typically 5 to 7 years. While we can visually check its placement during your boiler service, we recommend locating the 'replace by' date on your alarm. If it has expired, replace it immediately. Also, press the test button weekly to ensure the alarm is functioning correctly.Your peace of mind this winter starts with a fully serviced boiler and a fully functional CO alarm.