Smoke Alarm Requirements for London Landlords 2025 — Complete Guide
The Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022 changed the rules for all landlords. Carbon monoxide alarms are now required wherever combustion appliances are present. This guide explains exactly what you need, where, and what counts.
Updated Requirements from October 2022
The Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022, which came into force on 1 October 2022, extended the requirements for private landlords in England:
Smoke Alarm Requirements
- At least one smoke alarm on every storey of the property used as living accommodation
- Alarms must be in working order at the start of each tenancy
- If a tenant reports a faulty alarm, the landlord must repair or replace it promptly
Carbon Monoxide Alarm Requirements (New from October 2022)
- A carbon monoxide alarm must be installed in every room with a fixed combustion appliance, including gas boilers, gas fires, log burners, and solid fuel appliances
- This is an extension of the previous rules, which only covered solid fuel appliances
- This now applies to any room with a gas boiler — meaning any room where the boiler is installed (kitchen, utility room, bathroom, hallway) must have a CO alarm
What Type of Alarm Counts as Compliant?
The regulations do not mandate a specific type of alarm (hardwired, battery, interconnected), but alarms must be in working order. For practical compliance:
- Smoke alarms: Ionisation alarms (Kidde, FireAngel) or optical alarms. Optical alarms are preferred for bedroom corridors as they have fewer false alarms from cooking fumes.
- Kitchen alarms: A heat alarm — NOT a smoke alarm. Smoke alarms in kitchens trigger constantly from cooking. A heat alarm activates at a fixed temperature (57°C or a rate-of-rise) and is appropriate for kitchens.
- CO alarms: Must meet BS EN 50291-1. Replace after 7-10 years (check manufacturer's expiry date on unit).
HMO Requirements Are Stricter
For HMOs, most London borough licence conditions go beyond the minimum regulations:
- Interlinked smoke and heat alarms — when one triggers, all sound simultaneously. Essential for large HMOs where occupants on upper floors may not hear a downstairs alarm.
- Mains-powered alarms (Grade D, LD2 or higher) — battery-only alarms are typically not acceptable for HMO licensing in London boroughs.
- Alarms in every bedroom, every communal area, every landing.
Enforcement
Local authorities can require remedial action within 28 days. If the landlord fails to comply, the council can install alarms themselves and charge the cost to the landlord.
Frequently asked questions
Do I need a carbon monoxide alarm near the gas boiler in my London rental?
Yes — since October 2022, a CO alarm is required in every room with any fixed combustion appliance, which includes gas boilers. The boiler room (typically kitchen or utility room) must have a CO alarm. The alarm must be functioning at the start of each tenancy.
What type of smoke alarm do I need for a London HMO?
London HMO licence conditions generally require Grade D, Category LD2 interlinked smoke alarms — meaning mains-powered with battery backup, interconnected so all sound simultaneously, covering all sleeping areas, communal areas, and landings. Battery-only alarms are not compliant with most London borough HMO licence conditions.
How often do I need to test smoke alarms in a London rental?
The law requires smoke alarms to be tested and confirmed working at the start of each tenancy. There is no statutory requirement for monthly testing by the landlord during a tenancy — but best practice is to advise tenants to test monthly (press and hold the test button) and report faults immediately. For HMOs, monthly landlord testing is typically required under licence conditions.
Can I use wireless interlinked smoke alarms for an HMO in London?
Yes — wireless interconnected alarms (Aico, Ei Electronics) are acceptable and often more practical than hardwired in existing properties. They must be Grade D (have a battery backup) and Category LD2 coverage. Most London borough HMO licence conditions accept wireless Grade D systems. Check specific borough guidance before installation.