Home Smoke and CO Alarm Starter Kit - FireAngel FAKIT2

We recommend using an optical smoke alarm in hallways, living rooms, dining rooms and bedrooms, as they are good at detecting smouldering fires from soft furnishings and are less likely to be set off by cooking fumes from a connected kitchen.

Heat alarms are recommended for kitchens and garages as they do not sound false alarms from cooking fumes, vehicle fumes or steam.

Ionisation alarms are being phased out due to the small amount of radioactive material used in the detector chamber. Safelincs recommends optical smoke alarms where ionisation alarms were previously used.

We recommend testing alarms by pressing the test button built-in to the unit, as this is designed to simulate the detection of the target stimuli (usually smoke, heat, or CO) at the alarm sensor. For more detailed guidance, check the manual included with your alarm.

You should test your alarms regularly, preferably every week. Sign up to our free smoke alarm reminder service to receive regular reminders by email or text message.

Optical smoke alarms, also known as photoelectric detectors, have a high sensitivity to large particles in the air. They are slightly quicker at detecting slow-smouldering fires that produce a lot of smoke (such as fire from soft furnishings). They are suitable for living rooms and sleeping areas and are used near kitchens as they are less prone to false alarms. 

Ionisation smoke alarms use a small amount of radioactive material in the sensor chamber to detect fires, as such they are being discontinued. Safelincs encourages customers to purchase optical smoke alarms instead.

See also heat alarms for the most suitable protection in a kitchen.

Read more about how different smoke alarms work.

CO detectors should be installed near potential sources of carbon monoxide, essentially any fuel-burning appliances such as boilers, cookers and ovens, fireplaces (both open and enclosed burners), and portable generators. As you are likely to be most affected by CO in areas of your home that you spend the most time in it is advisable to install alarms in those areas as well, such as the living room and bedrooms. It is also worth noting that while one detector is better than no detectors at all, larger homes may require several detectors to cover the property fully.

Also note that carbon monoxide has been proven to spread into neighbouring properties through open windows and, in semi-detached or terrace houses, through loft spaces. If your property has an attached garage with a connecting door through to the house, it is recommended to fit a CO alarm inside the house leading from that doorway.

Battery powered carbon monoxide alarms can typically be installed wall-mounted or left free-standing on flat, level surface.

• Near an appliance: they should be placed within 1 to 3 metres horizontally from the appliance and between the height of the appliance to 150mm below the ceiling – i.e., not above a stove where it would be in the path of steam or fumes.
• In living spaces: they should be positioned close to where the occupant's head is likely to be most of the time – e.g., on your bedside table.

Combined smoke & CO alarms or mains-powered CO alarms are typically installed on the ceiling and should be at least 30cm away from any wall, light fitting, or other obstruction.

Do not install CO alarms within 3 metres of doors or windows, above radiators, or immediately close to anything that gives off steam or fumes like a cooker or shower room. Similarly, it is not recommended to install detectors in dusty areas such as workshops or garages.

For more information, please check the manufacturer's instructions – you can download the PDF manual from the relevant product page on our site. You can also watch our video guide to positioning CO detectors.

The symptoms of CO poisoning can range from mild flu-like symptoms such as headache, drowsiness, confusion, nausea and dizziness to more severe symptoms like breathing difficulties and irregular heartbeat. CO poisoning can ultimately lead to coma and death.

View more symptoms on our carbon monoxide information page.

No, normal smoke alarms cannot detect carbon monoxide (CO). Only combined smoke and CO alarms can detect both fire and carbon monoxide gas.

Since February 2022 all homes in Scotland must be fitted with interlinking smoke and heat alarms. In addition carbon monoxide alarms are required if there is a carbon-fuelled appliance or flue. 
View our list of alarms suitable for the Scottish regulations.

Different levels of carbon monoxide (CO) affect the body in  different ways. Exposure to large amounts of CO can cause sudden death, and prolonged exposure to low levels of carbon monoxide can have adverse effects on the body and brain.

This table shows the effects of different levels of exposure to carbon monoxide.

To change the battery in most smoke, heat and CO alarms you need to remove the alarms from the ceiling. Our helpful videos
 will guide you through replacing batteries in specific alarms. 

Smoke and heat alarms should ideally be installed in the centre of the ceiling. See our guide to positioning smoke and heat alarms for some helpful tips. Always refer to the manufacturer manual for specific information. 

Smoke alarms are more likely to ‘chirp’ at night due to lower temperatures.

The voltage of a battery drops as it reaches the end of its life. When a smoke alarm detects this lowered voltage, it emits a regular beeping sound before the battery finally expires, providing sufficient time to replace the battery before the alarm is deactivated.

Lower temperatures can also cause the voltage of a battery to drop. Our houses are often cooler at night, causing the voltage to drop, which triggers the low battery alert. It is particularly common in autumn and winter.