BS 5839-6 Grade D, mains-powered, 10-year sealed battery, fully interlinked. Aico RadioLINK or hardwired, with a heat alarm in the kitchen and CO alarms near gas appliances. Designed, installed and certified to BS 5839-6 in a day. Priced per property, fixed in writing.
07889 334849 · DS Electrical
Smoke alarms (BS 5839-6) ≠ Fire alarms (BS 5839-1). This page covers domestic, dwelling-house systems, the kind landlords, HMOs and homeowners need: ceiling-mounted alarms, mains-powered, interlinked, no panel. If you need a commercial fire alarm system, control panel, manual call points, sounders, zones, that's a different standard, see fire-alarms.html.
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Part P
BS 7671The 2022 amendment to the Smoke and Carbon Monoxide Alarm Regulations changed the duty on landlords. Building Regulations set the rules for new builds and for extensions that add a habitable room above or below the ground floor, such as a loft conversion. Old battery-only alarms do not meet that standard, and for rentals we recommend replacing them with mains-interlinked. Five property profiles below cover most of the calls we get.
Smoke and CO Alarm (Amendment) Regulations 2022: at least one smoke alarm on every storey, CO alarm in any room with a fixed combustion appliance. We fit Grade D interlinked, which goes beyond that legal minimum.
HMO licence conditions require a smoke alarm on every storey and a CO alarm in any room with a fixed combustion appliance other than a gas cooker; LACORS guidance, which Somerset Council follows, benchmarks an interlinked Grade D system for most shared houses. We design to your specific licence schedule, install in a day, and provide the certification pack the council demands.
Surveyors flag battery-only alarms in the homebuyer report. Bringing a Grade D system in before you list removes a negotiating lever from the buyer and protects the asking price.
If your only smoke alarms are the screw-on plastic disks with a 9 V PP3 battery in them, they are Grade F (battery-only) and legacy. Government guidance prefers sealed-for-life batteries over replaceable ones, and we recommend replacing them with mains-interlinked alarms.
Building Regulations (Approved Document B) require mains-powered alarms with battery back-up (minimum Grade D2, LD3) in new dwellings, and in extensions that add a habitable room above or below the ground floor, such as a loft conversion, or a ground-floor room without its own exit. We design to plan, install during second-fix, and certify for sign-off.
Every smoke and heat alarm has a 10-year service life printed on the back. Past that, the sensor is unreliable. Check the manufacture date, if it's 2016 or older, plan the replacement now.
Real DS Electrical install, mains-powered ceiling-mounted detector, BS 5839-6 compliant.
The standard isn’t complicated, one device per zone, smoke for circulation, heat for kitchens, CO near combustion appliances. We design the layout from a quick walk-round and fit to plan.
Optical smoke alarm on every storey: hallway downstairs, landing upstairs, top of any further staircase. These are the escape-route detectors, they wake you before fire reaches the only way out.
Living room and any room used as a TV room: optical smoke alarm.
Heat alarm only, Aico Ei3014 or equivalent. Smoke alarms in kitchens cause constant false alarms from toast and steam, so the standard mandates a heat sensor in the kitchen, interlinked with the smokes.
Carbon monoxide alarm in any room with a fixed combustion appliance: boiler cupboard, room with a gas fire, wood burner room. Hardwired and interlinked into the same system. Excludes gas cookers.
Where the HMO licence demands it (most do for higher-risk lets), an additional smoke alarm goes inside each let bedroom. Specified per the council schedule and your licence conditions.
Permanent unswitched live taken from the consumer unit on an RCBO-protected circuit, labelled at the board. So the alarms can’t be turned off at a wall switch and you know which device feeds them.
We don’t publish a price list. The price depends on the size and layout of the property, how many smoke, heat and CO alarms it needs, and whether RadioLINK or hardwired interlink is the right fit. Hardwired interlink in an existing property usually adds labour because of cable runs through ceilings. Final price comes after a survey or photo-based phone consult, and the survey is free.
Most domestic installs are a single-day job: arrive at 8, design the layout, run the cables or commission the RadioLINK modules, test every alarm, hand over the certification pack and walk the tenant or homeowner through every device before we leave.
Site survey or photo-based phone consult, we walk every storey, mark up smoke / heat / CO positions on a layout sketch, and confirm with you in writing before any work starts. No surprises on the day.
Dedicated lighting circuit at the consumer unit, ceiling-mounted bases, alarm heads paired and interlinked, every device tested with the test button and a smoke spray. Electrical Installation Certificate (EIC) and Part P notification through NAPIT.
Before we leave we walk the tenant or owner through every alarm: how to test, how to silence a nuisance trigger, what each LED colour means. Written service register with each alarm’s location, model, serial number and manufacture date for the 10-year replacement cycle.
BS 5839-6 is the British Standard for fire detection and alarm systems in domestic premises (houses, flats, HMOs). For most rented and modern homes you need Grade D, mains-powered alarms with a sealed back-up battery, fully interlinked, so that any one alarm triggering sounds every alarm in the property. Grade A (a full panel-based system with manual call points) is the commercial standard and covered under BS 5839-1, that’s our fire-alarms page. Grade F (battery only) does not meet Building Regulations for new dwellings or loft conversions, and we do not recommend it for rentals. We design and install Grade D every time unless an HMO licence demands otherwise.
In England, the Smoke and Carbon Monoxide Alarm (Amendment) Regulations 2022 (in force from 1 October 2022) require landlords in both private and social rented sectors to fit at least one smoke alarm on every storey of a rented property used as living accommodation, and a CO alarm in any room with a fixed combustion appliance (excluding gas cookers). For owner-occupied homes there is no blanket retrofit law, but Building Regulations (Approved Document B) require mains-powered alarms with battery back-up (minimum Grade D2, LD3) in new dwellings, and in extensions that add a habitable room above or below the ground floor, such as a loft conversion, or a ground-floor room without its own exit. For HMOs, LACORS guidance (which Somerset Council follows) benchmarks an interlinked Grade D system for most shared houses up to four storeys.
Both are fully BS 5839-6 Grade D compliant. Hardwired interlink uses a 3-core-and-earth cable between every alarm so the trigger signal travels down the cable, clean, neat, but requires lifting floors or chasing walls in an existing house. RadioLINK (Aico Ei3024 base + Ei100MRF module, or equivalent) uses an encrypted 868 MHz radio link between alarms instead, so each alarm only needs a permanent live feed at the ceiling rose. RadioLINK is the standard choice for retrofit because it avoids tearing up plaster and carpet, same compliance, much less mess and cost, finished in a day.
Optical and ionisation sensors degrade over time. Manufacturers (Aico, Kidde, Hispec, FireAngel) all specify a 10-year service life from the date of manufacture printed on the unit, after that the sensor is unreliable and the alarm must be replaced, even if it still beeps when you press test. We fit 10-year sealed-battery models so there’s no annual battery change for the homeowner or tenant, the whole alarm is replaced as a 10-year cycle. Heat alarms have the same 10-year service life. We label every alarm we fit with the install date and give you a written service register.
Mains alarms are part of the fixed installation. The work is notifiable under Part P when it needs a new circuit (we usually run a dedicated one), and it is always installed and certified to BS 7671. It must be carried out by a competent electrician registered with a Part P scheme (NAPIT, NICEIC, ELECSA or equivalent). DS Electrical is NAPIT registered (number 66245), every install we do is notified to your local Building Control automatically through NAPIT and you receive an Electrical Installation Certificate (EIC) for the new circuit, plus a written service register listing each alarm location, model, serial number and date of manufacture.
Further Reading
Site survey, written quote, install in a day, full certification pack. Phone or WhatsApp DS Electrical direct, no call centre, no chase-up.
07889 334849