World’s smallest mains heat alarm without light


£98.99 ex VAT

World’s smallest mains-powered recessed heat alarm. Designed to be discreet until there’s an emergency and without our Downlight.

Blends in seamlessly for discreet but complete, fully fire-rated safety.

Reliable connectivity to our smoke alarms to offer full coverage.

10-year sealed battery and back-up for safety that stands up.

People also bought.

Full heat detection coverage without light.

The smallest of its kind in the world, our heat alarm without Downlight provides the most discreet heat detection possible. By installing in the best position for optimum coverage rest assured this small but powerful plugin will ensure optimum fire safety coverage for your home – whilst keeping ceilings clear.



110V AC, 230V AC

Battery type

Non-replaceable CR2 10-year battery

Interlink frequency


Operating temperature

+4ºC to +38ºC (tested 0ºC to 55ºC)

Operating humidity

Up to 95% RH non-condensing

Power consumption

145aMh in non-alarm condition


Audible indicator minimum 85dB @ 3 metres in anechoic successive tones


30/60/90 - Solid Joist 30 - Metal Webbed Joist & I-Joist

Complies to

BS 5839: Part 6 Grade D1

Product colour



Cut-out size








Important bits.

Here you can find all the information you need to achieve streamlined results.

Design files.

.RFA, .LDT, and .IES files to help streamline your design.


Every product detail on one useful, downloadable datasheet.

Install sheet.

Download the installation sheet for all our technical know-how.

Test certification.

All our official certifications, ready for you to download.


At Lumi-Plugin® we believe everybody deserves beauty and safety in their home.
We are proud of our almost non-existent failure rate which is why our heat alarm comes with a 5-year guarantee.


  • What makes the One-Heat® alarm different?

    It’s the world’s smallest mains-powered heat alarm, to keep your space beautiful and most importantly – safe. We can do this by hiding all the technology behind our fully fire rated chassis, keeping functionality in great working and great looking condition.

  • Is the One-Heat® as safe as ordinary heat alarms?

    Yes. All our products including our heat alarm are fully accredited and certified by third-party regulators to ensure peace of mind across your entire home. Our heat alarm is more discreet but no less complete, making your space safe and stylish.

  • If the One-Heat® alarm fails do I have to replace the whole fixture?

    No. We’ve designed the product so you just replace the part you need. You can replace the heat alarm here. However, our heat alarm has a 10 year life so you don’t need to worry about this for a while.

  • Where would I need a heat alarm in my home?

    Heat alarms are designed to protect rooms like your kitchen, garage and loft areas based on the assumption that the build up of dust, moisture and fumes could cause issues such as false alarms.

Join our mailing list.

Sign up and receive information about our latest products and promotions.



Type it in, we’ll do the searching and deliver the goods.

Send us your plans.

Drop files here or
Max. file size: 256 MB, Max. files: 5.

    Join our mailing list and receive 20% discount on your first order.