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Battery Thermally Enhanced Optical Smoke Alarm (Thermoptek) with Escape Light - FireAngel ST-623E

10 in stock Expected dispatch: 3rd Nov
1 Customer Reviews
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£13.91 inc VAT
£11.59 ex VAT
Product Overview

Utilising FireAngel's Thermoptek thermally enhanced optical smoke sensor – the technology of choice for the UK's Fire and Rescue Service – the ST-623E is less prone to nuisance alarms caused by dust or cooking fumes and is quicker to detect smouldering fires than standard optical alarms. To aid evacuation in an emergency this product has an integrated extra-bright LED light which activates with the alarm to illuminate escape routes, making it a great choice for use in hallways or near stairs. For additional peace of mind FireAngel have also included Sleep Easy™ to silence low-battery chirps for 8 hours and Alarm Smart Silence™ so that it can still warn occupants of a real fire developing after silencing a nuisance alarm.

  • Battery: 2 x AA alkaline battery powered (included)
  • Warranty: 5 year manufacturer's warranty
  • Alarm Smart Silence™ feature helps provide maximum protection
  • Integrated extra-bright LED light helps evacuation during an alarm
  • Large test / silence button for hassle-free maintenance
  • Suitable for living rooms, bedrooms, hallways, and areas adjacent to a kitchen
  • Sleep Easy™ function temporarily silences the low battery warning chirp for 8 hours
  • Smoke alarm technology of choice for the UK's Fire and Rescue Service
  • Suitable for BS 5839-6: 2019 Grade F2 installations
  • Suitable for leisure accommodation vehicles (LAV)
  • Supplied with fixings; 2 x screws and 2 x rawl plugs
  • CE Marked and certified to BS EN 14604:2005
Technical Data
Product Code FAST623ER
Alternative Product Codes ST-623ER
Brand FireAngel
Battery Type

2 x AA batteries

Dimensions (HxDia)


Operating Temperature

+5°C to +38°C

Relative Humidity

30% to 90%

Sound Output



5 Years

Weight 0.11kg
Product Datasheets
FAQs (6)
Q. What smoke alarm should I use in a bedroom with an en suite bathroom?

It is usually recommended to install an optical smoke alarm in a bedroom. This is because optical smoke alarms are slightly quicker at detecting slow smouldering fires that can originate from upholstery type materials and over-heated wiring. Also, an optical smoke alarm would be less likely to sound a false alarm than an ionisation would, if steam/water droplets were present from the bathroom. Detectors should be installed as central to the room as possible; however for your application I would also consider the position of the en suite to make sure that the detector is not in the direct path of the joining door. This is just to try and avoid the chances of a false alarm. No detector is designed for use in bathroom areas.

Q. How do I safely dispose of my old smoke alarms?

Safelincs is signed up to Valpak's WEEE (Waste Electrical and Electronic Equipment) Distributor Take-Back Scheme (Registration ID: 7370). Private households can therefore drop off their electronic and electrical fire safety waste at their municipal recycling centre when they are purchasing new products from us. To find your nearest recycling centre, please visit

Q. How long do the batteries last in smoke alarms?

The 9V alkaline batteries last 12-18 months. Lithium batteries will usually last 5x longer than their alkaline counterparts, achieving around 5 years lifetime. Some lithium cells are also rechargeable, and when used in a mains-powered alarm may last for the entire functional lifespan of the alarm. Newer alarm models may also feature a "sealed" lithium battery. These batteries are specialist components which are designed to not be removed or need replacing by the user, and have been tested by the alarm manufacturer to ensure they last for the lifetime of the alarm.

Please Note: the actual lifetime of your batteries depends on how often the alarms are tested or activated, as sounding the alarm draws more power than when the alarms are "waiting" to detect fire. You should also read your alarm's manual to make sure you only use the recommended types and brands of batteries, as failing to follow these instructions may cause the alarm to malfunction, not alerting you in the event of a fire, and might also invalidate the warranty.

Q. What is the difference between an ionisation and an optical (photoelectrical) smoke alarm?

Ionisation smoke alarms detect fast flaming fires and are suitable for landings. Optical smoke alarms detect slow smouldering fires typical for burning soft furnishings. Optical alarms are suitable for living rooms and sleeping areas and are used near kitchens as they are less prone to false alarms. Please note that ionisation alarms contain a small amount of radioactivity.

Q. How long do smoke alarms last before needing replacement?

It is recommended that smoke alarms are replaced after 10 years. This is because the sensors in the smoke alarms become less sensitive and may not activate when a fire is present.

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Pricing & Availability

Model Stock Price
Product Code: FAST623ER Stock Level:
10 in stock Expected dispatch: 3rd Nov

£13.91 inc VAT

£11.59 ex VAT

Delivery Options

The following delivery options are available on this product.

Economy Delivery

£4.79 inc VAT - Orders will be delivered in 3-5 working days by Hermes

Express Delivery

£7.91 inc VAT - Orders will be delivered in 1-2 working days by Hermes

Excellent Warranty

This product is supplied with a 5 year manufacturers warranty as standard

Customer Reviews

1 customer has given this product an overall rating of 5 out of 5

Reviews by real customers

All of our product reviews are written by real customers that have purchased this product from us and are published without modification.

Rating: 5 / 5 Stars

Reviewed by: L O

A good product with a replaceable battery Fed up with smoke alarms that come with non replaceable batteries that only last half the time they are supposed to. This was a perfect find. Good value for money.

Published on: 24th August 2020

Looking for more information?

If you have any questions or would like more information about this product you can ask one of our specialists.

Direct Telephone 01507 464181


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