Smoke & Carbon Monoxide Alarm Requirements for London Landlords 2025
From 1 October 2022, all rented properties must have a carbon monoxide alarm in every room with a fixed combustion appliance. Here is everything London landlords need to know.
What the Law Requires
The Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022 extended the existing rules significantly. Since 1 October 2022 all private landlords in England must:
- Fit at least one smoke alarm on every storey of the rental property that is used as living accommodation
- Fit a carbon monoxide alarm in every room that contains a fixed combustion appliance — this now includes gas boilers, not just solid fuel
- Repair or replace any alarm as soon as possible after being informed that it is faulty
- Ensure alarms are in working order at the start of each new tenancy
Which Appliances Trigger the CO Requirement
A fixed combustion appliance is any appliance that burns fuel — gas, oil, solid fuel or biomass — that is permanently installed. This includes:
- Gas boilers (combi, system, heat-only)
- Gas fires and gas hob ranges (where fixed)
- Oil boilers
- Solid fuel stoves and open fires
- Wood-burning stoves
Electric heaters and electric hobs are not combustion appliances and do not trigger the requirement.
Where to Position Alarms
Smoke alarms perform best on the ceiling, at least 30 cm from any wall or light fitting. For CO alarms the manufacturer guidance varies but most recommend positioning at head height or on the ceiling, within 1–3 metres of the appliance. Do not place them directly above a cooker or in a poorly ventilated cupboard.
What Type of Alarm is Required
The regulations do not mandate a specific standard but best practice is:
- Smoke alarms: optical (best for smouldering fires) or combination optical/ionisation
- CO alarms: electrochemical sensor type, compliant with BS EN 50291
- Interlinked alarms are recommended in larger or multi-storey HMOs
Penalties for Non-Compliance
Local authorities can issue remedial notices requiring installation within 28 days. Failure to comply can result in a civil penalty of up to £5,000. This is separate from any liability arising if a tenant is harmed.
Best Practice During Gas Safety Checks
Many landlords combine alarm testing with annual Gas Safety Certificate visits. Our Gas Safe registered engineers can inspect existing CO alarms and note any that appear faulty during the CP12 inspection — though replacing alarms is the landlord's responsibility.
Frequently asked questions
Do I need a CO alarm if my property has only a gas hob?
A gas hob is a fixed combustion appliance so yes, since the 2022 amendment a CO alarm is required in the kitchen. The requirement now covers all rooms with fixed gas appliances, not only boiler rooms.
Can my tenant test the alarms on their own?
Yes — tenants can and should test alarms regularly by pressing the test button. The landlord obligation is to ensure alarms are working at the start of each new tenancy.
Do the regulations apply to HMOs?
Yes. HMOs are also subject to the Smoke and Carbon Monoxide Alarm regulations. HMOs have additional fire safety requirements under HMO licensing conditions and the Housing Health and Safety Rating System.
What is the penalty for not having alarms?
Local authorities can impose a civil penalty of up to £5,000 for non-compliance with a remedial notice. In the event of a death or injury linked to absent alarms, landlords face far more serious legal consequences.