Battery or mains-powered?
- Battery alarms are quick to fit, but rely on you testing them and changing batteries (or the whole unit, for sealed types).
- Mains-powered alarms have a battery backup and can be interlinked, so if one goes off they all sound. They're installed by an electrician.
- Heat alarms are generally used in kitchens, where smoke alarms give false alarms.
Where to fit them
As a minimum, have an alarm on every storey, typically in hallways and landings. Follow the manufacturer's instructions on positioning, and test them regularly.
Rules for landlords
In England, private landlords must fit a smoke alarm on every storey used as living accommodation and a carbon monoxide alarm in any room with a fixed combustion appliance (excluding gas cookers), and check they work at the start of each tenancy. See the GOV.UK guidance.
Never disconnect or remove the battery from an alarm because of false alarms; get it moved or replaced instead. If an alarm sounds, get out and call 999.
- You want mains-powered, interlinked alarms fitted
- You're a landlord updating alarms between tenancies
- Mains alarms are chirping, faulty or past their replacement date
Ask Steve about mains-powered alarms: call Steve or use the quote form to ask whether this is something he can help with and what it would involve.
Sources and further reading
- GOV.UK – Smoke and carbon monoxide alarms: booklet for landlords
- Electrical Safety First – Fire prevention tips
General guidance only, based on the sources above. Last reviewed October 2026. It isn't a substitute for an inspection by a qualified electrician.