Independent comparisons. We may earn from shop links. More info

Flush PIR sensor: which figures decide the fit

Updated: 23 October 2026

You have a plasterboard ceiling, a neutral at the rose, and a landing light that stays on. A flush PIR sensor is the usual answer, but a title that says 6 m does not tell you whether the body fits the hole, whether daylight holds the lamp off, or whether the printed LED watts are a safe maximum. This page walks those columns and does not rank the nine listings. The comparison is on the [Flush PIR sensor](/hub/electronic-surveillance/flush-pir-sensor) page. Peter F., DIY and tools editor, updated this on 20 October 2026 from amazon.co.uk listings, not a lab test. A qualifying purchase can earn a commission at no extra cost to you.

You have a plasterboard ceiling, a neutral at the rose, and a landing light that stays on.

Our top picks

SEBSON SEBSON IR_ES_A flush

Best overall

SEBSON SEBSON IR_ES_A flush
9.4/10about £13.99
View offer
SEBSON SEBSON IR_ES_E flush

Alternative

SEBSON SEBSON IR_ES_E flush
9.2/10about £14.99
View offer
Sensky Sensky BS041 recessed

Best value

Sensky Sensky BS041 recessed
9.0/10about £12.99
View offer
On this page
  1. 1.Cut-out and void
  2. 2.Three conductors
  3. 3.Time, lux and LED watts
  4. 4.IP and what the listing does not say

Cut-out and void

The hole is not one size, and a trade sheet’s 63 mm figure is not a stand-in for a blank cell. Only SEBSON IR_ES_E (Ø63–66 mm) and Sensky BS041 (65–70 mm) print an opening. IR_ES_A, IR_ES_B, IR_ES_C, IR_ES_D, IR_ES_FA, the Zquqwa and the mini IR_BS_A leave the cut-out unstated. A reviewer’s hole saw is not the listing. Danlers, Elkay and Autenco use their own holes. Do not paste them onto a blank amazon cell. IR_ES_D is 40 mm tall and can also sit on the surface. The cutting order is on how to install a flush PIR sensor.

Three conductors

Three-wire means a permanent live, a neutral, and a switched live to the lamp. It does not mean any three colours in a switch drop. A typical UK switch drop has no neutral. The ceiling rose usually does. Follow the diagram in the box, and stop if you cannot name the three conductors. Several frequency cells print 60 Hz, and UK mains are 50 Hz.
SEBSON SEBSON IR_ES_A flush

Testsieger

SEBSON SEBSON IR_ES_A flush
9.4/10about £13.99
View offer

Time, lux and LED watts

Most rows offer about 10 seconds to 15 minutes and a photocell from 3 to 2,000 lux. A WC needs a longer delay than a hallway, because someone standing still is invisible to a PIR. IR_ES_E and IR_ES_D reach 30 minutes. IR_BS_A stops at 8 minutes. LED watts are a maximum running figure, not a downlight count and not an inrush rating. Printed LED or energy-saving loads are 300 W on the Zquqwa, 400 W on IR_BS_A and IR_ES_C, 600 W on IR_ES_A, IR_ES_B and IR_ES_D, and 1,000 W on IR_ES_E and IR_ES_FA. Sensky prints none. The Lighting Industry Association says LED inrush can damage PIR contacts. No kept listing prints an inrush current.

IP and what the listing does not say

IP20 means a dry room: fingers, not spray. Sensky says the BS041 is not for bathrooms or wet spaces. IR_ES_A, IR_ES_B, IR_ES_C and the Zquqwa are indoor IP20. IR_ES_D and IR_ES_E say indoor and give no IP rating. Only IR_ES_FA claims IP54, with one bullet saying indoor and outdoor while another field says indoor. IP54 is not a bathroom-zone approval. The measurements are on PIR sensor bathroom zones. No kept row states BS EN 60669-2-1. IR_ES_B swivels, which belongs on the best flush PIR sensor page. You can shortlist from the columns. You cannot crown a winner here.

Common questions

What hole do I need for a flush PIR sensor?
You need the hole printed on the listing you are buying, not a generic 63 mm. In this set only IR_ES_E states Ø63–66 mm and Sensky states 65–70 mm. The other seven leave the cut-out unstated. Danlers and Elkay use about 63–64 mm, and Autenco uses 73–75 mm with a 95 mm void, but those are different products. A reviewer’s saw size is not the specification, so leave it off the shortlist.
Does a ceiling PIR need a neutral?
Yes. Every kept listing is 3-wire, which means permanent live, neutral, and switched live. A wall switch drop often has no neutral. The ceiling rose usually does. If you cannot point to those three conductors, stop and get a competent person rather than guessing from colours on a forum.
What does 3-wire mean on these listings?
It means the sensor needs a permanent supply, a neutral, and a switched live to the lamp. Danlers uses brown, blue, and black on its own trade unit. That colour map is an example, not the diagram inside an amazon box that does not print one. Earth, where it exists in the cable, is not a substitute for the neutral.
Is 600 W LED the number of downlights I can fit?
No. 600 W is a maximum running load printed for LED or energy-saving lamps on IR_ES_A, IR_ES_B, and IR_ES_D. It is not a downlight count, and it is not the inrush current at the moment the lamps strike. The LIA guide says that inrush can damage sensor contacts. No row in this set prints an inrush figure.
Why do some amazon tables say 60 Hz?
Because the frequency cell says 60 Hz. UK mains are 50 Hz, which is what Danlers and Autenco specify on their own sheets. Do not read 60 Hz as the supply in a British house. A description of IR_ES_E has also shown 50 Hz, and that clash is a reason to treat the frequency cell as unsettled.
Is IP20 enough for a bathroom?
No, not in zone 1 or zone 2. IP20 is a dry-room mark. Those zones need at least IPX4, and ordinary 230 V switches are barred there. Sensky explicitly excludes bathrooms. IP54 on IR_ES_FA is still not a zone approval. The zone page covers the measurements in metres.
How long should the timer run in a WC compared with a hallway?
A hallway can use a short delay inside the common 10 seconds to 15 minutes window, because people keep moving. A WC needs longer, because a person who stops moving disappears to a PIR. IR_ES_D and IR_ES_E reach 30 minutes. The mini IR_BS_A stops at 8 minutes in fixed steps, so it is a weak cloakroom choice if you wanted fifteen minutes.

Related pages

Flush or surface mount PIR sensor

Flush PIR sensor

PIR sensor bathroom zones and a flush ceiling switch

Best flush PIR sensor for one dry-room job in the UK

How to install a flush PIR sensor in your UK ceiling

Sources

Public UK sources from the research digest. Shelf prices, stars and review counts are the figures stored with these nine amazon.co.uk listings. No laboratory test was carried out. October 2026.

  1. Approved Document P, 2013 (retrieved 22 October 2026)
  2. GOV.UK: building work, replacements and repairs (retrieved 22 October 2026)
  3. GOV.UK: Electrical Equipment (Safety) Regulations 2016 (retrieved 22 October 2026)
  4. SELECT bathroom zones guide, 2022 (retrieved 22 October 2026)
  5. IET: section 701, locations containing a bath or shower (retrieved 22 October 2026)
  6. Danlers CEFL PIR user guide (retrieved 22 October 2026)
  7. Autenco flush PIR data sheet (retrieved 22 October 2026)
  8. Lighting Industry Association: inrush currents (retrieved 22 October 2026)