How To Test A Carbon Monoxide Detector

From 1 October 2015, the new Smoke and Carbon Monoxide Alarm (England) Regulations 2015 required landlords to install smoke and CO alarms in England.

Not only must landlords ensure that both smoke and CO alarms are installed, but they must be checked and ‘in proper working order on the day the tenancy begins if it is a new tenancy.’ Whilst checking and testing a smoke alarm is relatively straightforward, there is less understanding amongst many landlords on how to test a CO alarm properly. 

This is particularly an issue as the actual test button on a CO alarm only tests that the battery, buzzer and electronics work and not the actual gas sensor itself. Testing with a "known source of calibrated test gas" on installation and annually is already a Standard requirement in the USA. 

This is the only way to ensure a CO alarm is fully working. Sensor inclusive testing of CO alarms can be easily, quickly and cheaply carried out by an engineer or competent DIY'er with a Detectagas kit

Fully Patented, Detectagas is non-flammable, non-hazardous and ozone friendly and has won more industry awards than any other product in the gas detection sector. 

Managing Director of Gas Safe Europe John Stones, who has campaigned for over 20 years to raise the awareness of carbon monoxide and developed Detectagas, said:

“The life expectancy of the sensor on a CO alarm is limited as they age naturally but can also be unpredictable due to airborne pollutants such as cooking fumes and cigarette smoke. “Many reports from the USA and UK, including the HSE, have found CO alarm reliability lacking with around 45% found to be no longer sensing gas in tests. One report even found that 16% of new alarms were not working out of the box. “We are now working with BSI to develop a British Standard (PAS) for the sensor inclusive testing of domestic CO alarms. It will take some time but in the meantime the Energy Act 2015 is clear. A landlord must have a working carbon monoxide alarm and the only way to ensure that it’s fully working is with a sensor inclusive test.”

For more information about where to buy DETECTAGAS®, call 0845 73 4760 or visit

View Related Handbook Page

Smoke and Carbon Monoxide Alarms

The Smoke and Carbon Monoxide Alarm (England) Regulations 2015 affect almost every rented property (including existing tenancies) and commenced on 1 October 2015.