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Replacement for BRK 790MBX Mains Powered Heat Alarm

Discontinued Product - No Compatible Replacement

This product has been discontinued.

alternative product

Kidde Firex Mains Powered Alarms with Alkaline Battery

  • 230V mains powered with alkaline back-up battery
  • Available in Optical and Heat versions
  • Interlink with up to 24 units
  • Suitable for BS 5839-6: 2019 Grade D2 installations
  • Kitemarked and CE marked
  • Please note: alarms are sold individually
  • Also suitable for both the Welsh and Scottish 2022 legislation

£21.00 inc VAT

£17.50 ex VAT

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Product Overview

The BRK 790MBX heat alarm with push-fit base is no longer available for sale. This BRK 690MBX heat alarm is the exact same detetcor and alarm head as your outgoing 790MBX heat alarm ;ndash; the only difference is that the spare base supplied is a different version. The new detector head fits directly onto your existing push-fit base and is guaranteed compatible with your existing system.

Like your old 790MBX unit, the replacement is a mains powered heat alarm designed to be installed in kitchens where smoke alarms may be accidentally triggered by normal cooking fumes. It is designed to be simple to install, maintain and use. Hardwire interlink can be made with up to 12 alarms in the range, and mains power is supplemented with a 9V alkaline backup battery.

  • Direct replacement unit for the BRK 790MBX
  • Genuine heat alarm made by BRK – guaranteed compatible
  • Power: 230V mains powered with back-up battery
  • Back-up Battery: replaceable 9V alkaline back-up battery (included)
  • Warranty: 5 year manufacturer's warranty
  • Easy to install onto your existing push-fit base
    • BRK twist-fit base included to keep as a spare
  • Combined Test & Silence button feature
  • Replacements are also available for the BRK 760MBX and 770MBX mains powered smoke alarms
  • CE and Kitemarked to BS 5446-2: 2003
  • Manufacturer's 5 year warranty
  • Product warranty and life commences from date of purchase

The simple installation process of the 790MBX replacement alarm eliminates the need for an electrician, though you must ensure that mains power to all interlinked alarms is cut before beginning work. The interlink wire can carry a live electric current between alarms if they are powered from different circuits.

Technical Data
Product Code BK79RA
Alternative Product Codes 790MBX, BRK790MBX, 690MBX, BRK690MBX, BRKEHA
Brand BRK
Back-Up Battery

Replaceable 9V Alkaline

Dimensions (HxDia)

58 x 140mm (including base)

Operating Temperature

+5 °C to +38 °C

Relative Humidity

10% to 85%

Sound Output


Weight 0.31kg
Product Datasheets

Key Product Features

The 690MBX alarm head is exactly the same unit as the 790MBX

LED indicators show power supply and alarm activity status

Combined Test & Hush button to check function and silence alarms

Same manufacturer as your original 790MBX heat alarm

What's Included?

Every BRK BK79RA is supplied with the following components.

  • 1 x BRK 690MBX heat alarm
  • 1 x 9V replaceable alkaline battery
  • 1 x Spare twist-fit base
  • 1 x Screw fixing set (screws & rawl plugs)
  • 1 x Instruction manual

Excellent Warranty

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

Looking for more information?

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

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