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The Firex KF20 optical mains smoke alarm from Kidde with a 9v battery backup is one of the most popular 230v alarms in the UK (replaced the discontinued Kidde 4973). Interconnectable to up to 23 other Firex or Kidde Slick mains alarms and round for easy lining up, installation of this optical (also know as photoelectric) smoke alarm could not be easier. Fully conforming to BS 5839-pt6 Grade D, the 4973 alarm has a 6-year warranty and a hush and test button as standard. The Firex KF20 has a lower lifetime running cost compared to most alarms due to its reduced energy consumption.
Note - in the options, there is a long life version with a lithium backup battery that is guaranteed to last the 6 years of the alarm warranty. Standard backup batteries need replacing every 12 months.
Optical alarms are suitable for smouldering fires and are to be used in hallways, bedrooms, and offices - a house should have a combination of optical and ionisation
Do not use in or too near to a kitchen or shower room
Fixing requires two little screws and wallplugs (included) to screw to ceiling
  • 6-year warranty with 6 year backup battery option
  • BSi Kitemarked to BS 58396 pt. 6, CE Marked
  • Interconnectable to 23 other alarms from the Firex and Kidde Slick range
  • Diameter 127mm
  • Depth 39mm
  • Manufactured by Kidde Firex
Customer reviews
Average rating:
5.00 (Votes: 3)
Rating of votes (3)
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  • Patrick Lavelle
    Apr 4, 2017, 10:36
    Itis a pleasure to deal with this company, excellent website easy to navigate, Irequested to exchange an item, contacted customer service spoke to knowlegable polite and helpfull person. First class service all round thank you.
  • Rosemary Medlicott
    Dec 3, 2015, 09:04
    Quick fast and efficient service, very good, thank you
  • Rosemary Medlicott
    Nov 30, 2015, 13:47
    Very quick and efficient, arrived at time stated, no problems at all, will use the service again. Thank you.

Firex KF20 Optical Smoke Alarm

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    Score: 5.00 (votes: 3)
    Reviews: 3

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