Smoke Alarm Installation in North West London

What the 2022 amendment changed for landlords

The Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022 came into force on 1 October 2022 and extended the 2015 rules in two ways. Carbon monoxide alarms became required in any lived-in room with a fixed combustion appliance, not only solid fuel ones, with gas cookers excluded. And landlords gained a duty to repair or replace an alarm, as soon as reasonably practicable, once a tenant reports it faulty.

The day-one duty stayed: every alarm must be checked as working on the day a new tenancy begins. The council enforces the rules through a remedial notice, with a penalty of up to £5,000 if the notice is not complied with. Our full guide to the rules, room by room, is linked below. This page is about what to fit.

Mains-interlinked or ten-year sealed battery?

For a let property, mains-wired interlinked alarms are the better installation, and sealed battery alarms are the acceptable minimum. The 2015 Regulations do not say which type to use. GOV.UK recommends alarms that comply with BS 5839-6, and says sealed-for-life batteries are a better option than replaceable ones. Mains alarms have a backup battery, so they keep working in a power cut, and nobody can borrow the battery for the TV remote.

Interlinking means a fire in the kitchen sets off the alarm on the landing outside the bedrooms. That is the alarm that wakes people. Sealed battery alarms are quicker to fit, and radio-interlinked versions now exist, which suit a property where running cable would damage decoration.

• Choose mains-interlinked for HMOs, licensed properties, rewires, loft conversions and anywhere the licence asks for it
• Choose sealed battery, ideally radio-interlinked, for a quick compliant fix in a single-household flat with no licence condition
• Never replace a working mains system with battery alarms; that is a downgrade

What do the BS 5839-6 grades and categories mean?

BS 5839-6 grades a home alarm system by its power supply and categorises it by how much of the home it covers. The grade tells you how the alarms are powered. The category tells you where they go. Under BS 5839-6:2019 with its 2020 amendment, Grade D1 means mains-powered alarms with a tamper-proof standby battery. Grade D2 is mains-powered with a user-replaceable standby battery. Grade F1 and F2 are battery-only systems, with tamper-proof and replaceable batteries respectively. For categories, LD3 covers the escape route only, meaning halls and landings.

LD2 adds the main living room and the kitchen. LD1 covers every room where a fire could start. The standard's own table recommends Grade D1 and Category LD2 for rented homes, with a heat alarm in the kitchen. That is a recommendation, not the law. It is a good target when you are fitting from scratch, and the price difference over a bare LD3 system is a few extra heads.

What Harrow's licensing guidance asks for

If your house or flat is in one of Harrow's selective licensing wards, read the council's fire safety guidance before buying alarms. It is based on the LACORS housing fire safety guide. For a normal-risk single-household house, it asks for a Grade D, LD3 system: interlinked mains-wired smoke alarms with integral battery back-up in the escape route at ground and first floor, and an interlinked alarm in any cellar. The same guidance covers flats above shops, which are common on the parades around Kenton, Wealdstone and Burnt Oak. Where the flat has its own entrance and is separated from the shop by 60-minute fire-resisting construction, little more is needed.

Where you reach the flat through the shop, or the shop is a high fire risk, the guidance says the flat's alarm system should be extended into the commercial premises and interlinked. That is a different job, and we price it after a visit. Licensed HMOs fall outside the 2015 Regulations' main duties, but GOV.UK notes that licence conditions impose similar requirements, and in practice HMO conditions usually ask for more. Brent and Barnet set their own HMO conditions. Read the licence, not a general guide.

Where do heat alarms and CO alarms go?

A heat alarm goes in the kitchen, and a CO alarm goes in the same room as the boiler, fire or stove. Smoke alarms false-alarm in kitchens because of toast and steam, and an alarm that keeps going off tends to get disconnected. A heat alarm reacts to a rise in temperature instead. GOV.UK is clear that heat detectors are not a replacement for smoke alarms, so the hall and landing still need smoke alarms.

For carbon monoxide, the legal trigger is a fixed appliance that burns fuel for heat, in a room used as living accommodation. Bathrooms count. Mount the CO alarm as the manufacturer's instructions say, usually at head height and away from the appliance's immediate airflow. A CO alarm can be interlinked with the smoke system on some ranges, which is worth doing in larger houses.

Is fitting mains smoke alarms notifiable work?

Sometimes. Under the Building Regulations, installing a new circuit is notifiable. Mains smoke alarms on their own dedicated circuit from the consumer unit are therefore notified to Building Control. Alarms taken from an existing lighting circuit are not a new circuit, so they are not notifiable, but the work is still tested and certified with a Minor Works certificate.

Either way you get the paperwork. A conveyancer, a licensing officer or an insurer may ask for it, and the next EICR inspector will test the alarm circuit as part of the fixed installation.

Testing at the start of a tenancy and after a report

The check must happen on the day the tenancy begins, not the week before. Press the test button on each alarm, confirm the interlinked ones all sound, and write down the date, the time and who did it. GOV.UK suggests the tenant signs the inventory to confirm the alarms were tested and working. When a tenant reports a fault, the duty is to check it and repair or replace it as soon as reasonably practicable.

A chirping alarm usually means a low backup battery or an alarm at the end of its life. Check the replace-by date printed on the alarm. If it has passed, replace the head rather than the battery. On most mains systems the new head fits the existing base, which makes this a short visit.

What affects the price?

How many alarms, and whether they are wired, interlinked or battery. Swapping old mains heads for new ones on the same bases is a short job. A new wired system in a house with no existing alarms means lifting floorboards or running cable on the surface. Radio-interlinked alarms cost more per head but save that labour. The number of storeys, the heating appliances that need CO alarms, and any licence condition that sets the grade decide the alarm count.

Certificates and defined jobs are a fixed price confirmed before we attend; repairs are charged by the hour, with the rate and an estimate confirmed before we attend.

Where we fit alarms

We fit alarms across Harrow, Kenton, Stanmore and Edgware, and in Wealdstone, Queensbury, Wembley, Burnt Oak, Mill Hill and the nearby areas. Much of our work is in 1930s semis, where the escape route is a single hall, stair and landing, and in flats over shops on the local parades. Harrow's selective licensing wards include Edgware, Roxeth, Greenhill, Marlborough and Wealdstone North and South, where the council's fire safety guidance applies.

Electricians by area: Electrical work in Harrow, Electrical work in Kenton, Electrical work in Stanmore, Electrical work in Edgware, Electrical work in Bushey, Electrical work in Colindale, Electrical work in Hendon, Electrical work in Mill Hill, Electrical work in Northolt, Electrical work in Northwood, Electrical work in Pinner, Electrical work in Ruislip and Electrical work in Wembley.

What we will not do

We fit domestic smoke, heat and CO alarms. We do not design, install or certify commercial fire alarm systems to BS 5839-1, emergency lighting, or fire risk assessments for HMO common parts, and we will refer you to a specialist for those. In Scotland every home must have interlinked fire alarms under Scottish rules; we work in England only.

Why people trust us

• Work by registered electricians, certified, and notified to Building Control where the job requires it
• A walk-in office on Kenton Lane, not a serviced address
• The fault found and the options explained before we go further
• A time slot rather than a morning-or-afternoon window
• Work photographed before and after, and reported
• We tell you when you do not need something we sell

We are building a review profile under this name and would rather show you none than borrow someone else's. Ask us for references from landlords and we will put you in touch.

Official sources

• legislation.gov.uk: The Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022
• GOV.UK: Smoke and carbon monoxide alarm regulations, Q&A booklet for landlords (updated 29 July 2022)
• Harrow Council: Selective licensing fire safety guidance
• GOV.UK: Approved Document P, electrical safety in dwellings (notifiable work)
• Aico: BS 5839-6:2019+A1:2020 grades and categories explained

Last reviewed October 2026 by EliteShires Property Services.