HEIMAN HK-735ESY-WT-1 Interlinked CO Detector with LCD

Interlinked: The HEIMAN HK-735ESY-WT-1 is a battery-powered carbon monoxide detector with an LCD, audible and visual alarm, and claimed wireless interconnection with compatible units. Its display is intended to show CO concentration, while the listing also claims a sealed 10-year battery and BSI Kitemark certification.

At a glance

LCD is claimed to show carbon monoxide concentration in ppm.
Manufacturer describes wireless RF interlinking so connected alarms sound together when one detects danger.
Listing claims a sealed CR123A battery with a 10-year life, plus pre-alarm, fault and end-of-life alerts.
Audible and visual alarm. The listing claims an 85dB sound level at 3 metres.
Manufacturer claims BSI Kitemark certification and compliance with BS EN 50291-1:2018, with CE and UKCA markings.

Price

£28.04Save 15%

Reference price: ~~£32.99~~

Price checked: 14 Nov 2026

View offer Ahead of Black FridayExplore the selection

Pros and cons

Pros

An LCD concentration readout can offer more context than an alarm that only signals with sound.
Wireless interlinking is intended to spread an alert across compatible linked units without wiring between alarms.
The claimed sealed 10-year battery avoids routine battery replacement during its stated service life.

Technical specifications

10 specifications

Identity
Brand	HEIMAN
Model	HK-735ESY-WT-1

Display
Screen technology listed	LCD

Power and sensing
Power configuration	Battery Powered
Sensor type	Electrochemical
Alarm	Audible & Visual

Dimensions and installation
Dimensions listed	8.6D x 8.6W x 3.5H centimetres
Weight listed	143.55 Grams

Materials and appearance
Material listed	ABS+PC
Colour	White

What to know before buying

Listing details to confirm

The listing identifies the product as model HK-735ESY-WT-1, while its description names HM-735ESY-WT and HM-735 alarms for pairing. The stated package lists one CO detector, a heat alarm, an installation kit, a manual and three smoke alarms, but the title and feature copy describe a single interlinked CO detector. Confirm the selected listing’s exact model, compatible interlink system and bundle contents before buying. The 10-year battery life, certification and alarm performance are manufacturer claims, not independently verified here.

What’s in the box

Included

1 x Carbon monoxide detector
1 x Heiman heat alarm
1 x Installation kit
1 x Product manual
3 x Smoke alarms for home

Who is it for?

A good fit for

Buyers wanting a CO detector with a concentration display as well as audible and visual alerts.
Homes or other spaces where a compatible wireless interlinked alarm system is wanted, after confirming the units can pair.
Buyers looking for a detector described for homes, caravans, campervans, boats or garages.

Less suited to

Buyers who need confirmed compatibility with a particular existing alarm network without checking the model first.
Buyers who require independently verified performance or certification evidence beyond the listing claims.

HEIMAN HK-735ESY-WT-1 Interlinked CO Detector with LCD · photo 2 — Additional product photo 2

Customer reviews on Amazon

4.4 / 5 · 40 ratings

5 stars54%54%
4 stars38%38%
3 stars4%4%
2 stars0%0%
1 star4%4%

An aggregate rating shows a generally positive but not unanimous response, with ratings concentrated in the four- and five-star categories and a small low-rating share. No written customer feedback is supplied, so the figures do not establish what buyers liked or why some rated it poorly. They cannot confirm the claimed LCD readout, interlinking or battery life.

Frequently asked questions

Does this detector display CO levels?

The listing claims its LCD shows the carbon monoxide concentration in ppm. This is a manufacturer claim.

Can it interlink with other alarms?

The listing describes wireless interlinking, but uses differing model names for the detector and compatible alarms. Confirm compatibility with the specific units you intend to pair.

How long does the battery last?

The listing claims a sealed CR123A lithium battery with a 10-year life. Actual battery life is not independently verified here.

What is included in the package?

The listed contents are one CO detector, one Heiman heat alarm, one installation kit, one product manual and three smoke alarms. This conflicts with the single-detector presentation, so confirm the bundle for the selected listing.