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How to install a wireless smoke alarm

Updated: 21 October 2026

You have a battery pack from amazon.co.uk on the table and about an hour before you want the first test beep finished. This is how to install a wireless smoke alarm from the sets in the [wireless smoke alarm comparison](/hub/fire-protection/wireless-smoke-alarm): ceiling position, a fixing that stays up, then a test where one button makes every linked head sound. If you are still choosing the pack, use the [buying guide](/hub/fire-protection/wireless-smoke-alarm/sub/wireless-smoke-alarm-buying-guide) first. Stop if the job is mains. These steps are for sealed or replaceable battery heads. A qualifying purchase can earn a commission at no extra cost to you.

You have a battery pack from amazon.co.uk on the table and about an hour before you want the first test beep finished.

Our top picks

LINKD LINKD smoke, heat and CO

Best overall

LINKD LINKD smoke, heat and CO
9.2/10about £99.99
View offer
WISUALARM WISUALARM SA20A 2-pack

Alternative

WISUALARM WISUALARM SA20A 2-pack
9.2/10about £18.69
View offer
X-Sense X-Sense HS21

Best value

X-Sense X-Sense HS21
8.4/10about £47.99
View offer
On this page
  1. 1.Where each head goes
  2. 2.Fix the base before you trust the pad
  3. 3.Power, pair, then twist on
  4. 4.Test the local alarm and the interlink

Where each head goes

Put smoke alarms on the ceiling, at least 300 mm from a wall and from a light fitting. A head tucked into the corner sits in a dead patch of air. Halls and landings are the circulation spaces that wake you. The kitchen gets the heat alarm, not another optical head. In this comparison the heat head is the one in the X-Sense HS21, the LINKD kit, the XINDUM kit and the CPVAN bundles. The WISUALARM S05 3-pack has no heat head. Carbon monoxide does not have to radio-link to the smoke and heat group. If you are unsure whether a textured coating is asbestos, do not drill it to find out.

Fix the base before you trust the pad

Do not drive a screw through a cable. Screws are the mount that reviews support. Use them on an ordinary ceiling. One UK review of the WISUALARM SA20A had a taped unit fall after about a week. An alarm on the carpet does not detect smoke on the ceiling. Adhesive is reasonable when asbestos means you must not drill. Do not use a pad on textured Artex. Twist the alarm onto the base only after the base is firm.
LINKD LINKD smoke, heat and CO

Testsieger

LINKD LINKD smoke, heat and CO
9.2/10about £99.99
View offer

Power, pair, then twist on

Pair on the table, then carry the heads to the ceiling. Pre-linked kits, including LINKD, XINDUM and the CPVAN bundles, are sold as already grouped. A spare has to join that family, not CPVAN's older SM11R line. There is no universal four-press code that every brand shares. Standalones do not pair. The XUK Wi-Fi alarm pairs to 2.4 GHz Tuya or Smart Life, which is a phone account, not a link to these radio kits. Which rooms the law in your nation names is on the rules page. Do not open a tamper-proof cell.

Common questions

Should the alarm go on the ceiling or the wall?
Smoke and heat alarms in this kind of home system go on the ceiling, at least 300 mm from walls and from light fittings. A wall is the wrong plane for those heads because smoke reaches the ceiling first and the corner is a dead spot. Carbon monoxide can be sited differently; use the distances in that alarm's leaflet, and do not assume it must join the radio group.
Are sticky pads acceptable?
Screws are the better fixing on a normal ceiling. Pads and tape are what Scottish advice allows when asbestos means you must not drill, and they sometimes hold on a smooth painted surface. They also fail: a WISUALARM review lost a head after about a week. If you use adhesive, clean the surface, press it properly, and test that the head is still up a week later. Do not stick a pad to flaky Artex and call it fitted.
How do I add a spare to a pre-linked pack?
Use a spare from the same family and follow that maker's pairing steps on the table, then mount and test. LINKD talks about adding heads up to 30. CPVAN's second generation does not accept SM11R. There is no shared button code across X-Sense, CPVAN and WISUALARM. If the new head will not make the others sound, it is not in the group, whatever the app-free LED looks like. Do not mix in a FireAngel or an XUK and expect the radio net to grow.
How do I prove the interlink works?
Press and hold the test button on one fitted head until every other linked head sounds, then repeat from a second head. You should hear the kitchen and the landing, not only the unit under your finger. Do this on the day you fit them and at least monthly after that. A factory pre-linked line is the starting claim. The sound test is the proof. If one head stays silent, stop and re-pair before you trust the house.
Where does the heat alarm go, and how often do I test?
The heat alarm goes on the kitchen ceiling, with the 300 mm clearances, not in the hallway and not instead of the smoke alarms. Test every alarm at least monthly. On a radio kit, monthly means the all-sound check, not a glance at a green LED. Hush, including a 10-minute silence, is for a known false alarm. It is not the monthly test, and it is not a reason to take the battery out.

Related pages

Wi-Fi versus radio interlink

Wireless smoke alarm

Best wireless smoke alarm for the UK home you have

How to choose a wireless smoke alarm for your home

Smoke alarm rules in Scotland, England, Wales and NI

Sources

Public UK sources listed below, plus amazon.co.uk shelf prices and ratings for these ASINs, last checked on 19 October 2026.

  1. Scottish Government: fire and smoke alarms in Scottish homes (retrieved 19 October 2026)
  2. Scottish Government: where and what to buy (retrieved 19 October 2026)
  3. Scottish Government: Tolerable Standard guidance on fire and carbon monoxide detection (retrieved 19 October 2026)
  4. Scottish Government: changes to fire safety laws (retrieved 19 October 2026)
  5. GOV.UK: smoke and carbon monoxide alarms, England regulations Q&A for landlords (retrieved 19 October 2026)
  6. legislation.gov.uk: Wales regulation 5, smoke alarms (retrieved 19 October 2026)
  7. GOV.WALES: fitness for human habitation guidance (retrieved 19 October 2026)
  8. EDA summary of BS 5839-6:2019 changes (retrieved 19 October 2026)