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Replacement Smoke Alarm for BRK 660MBX and 670MBX - easichange® SBBRKSM

660mbx push replacement smoke alarm showing a wiring base with coloured arrows pointing to front cover and sensor unit
4.9 out of 5 stars

20+ In Stock

Estimated dispatch: Tomorrow

£41.50 inc VAT

£34.58 ex VAT

Standard Delivery

Will usually be delivered in 2-3 working days

£4.20 inc VAT

Next Day Delivery

Will usually be delivered the next working day

£7.00 inc VAT

The SBBRKSM easichange® kit replaces the discontinued BRK 660MBX optical and 670MBX ionisation smoke alarms and fits onto your existing BRK twist-fit alarm baseplate so there's no need for any DIY or an electrician. The kit consists of the replacement optical smoke alarm head with pre-connected easichange® adaptor, an easichange® removal tool, a quick change guide, and the full alarm manual.

The SBBRKSM is a mains powered smoke alarm with a replaceable 9V alkaline backup battery like the 660MBX and 670MBX that it replaces. The optical sensor technology improves on the detection of slow smouldering fires and reduces the chances of false activations. Featuring a hardwire interlink allowing compatible easichange® alarms to communicate with each other over the same wiring as your old BRK alarms, so that all will sound the alarm if one detects a fire.

  • Optical detector replacement for BRK 660MBX and 670MBX alarm heads
  • Simple replacement process with Quick Change Guide
  • Fits onto your existing BRK twist-fit alarm baseplate
  • BRK alarms allow linking up to 12 units, while a system of easichange® alarms supports up to 40
  • Single test / hush button for easy maintenance and silencing false alarms
  • Optical sensor for improved detection and reduced false alarms
  • Supplied with FREE easichange® replacement tool
  • Smoke alarm CE Marked, UKCA Marked, and Kitemarked to BS EN 14604: 2005
  • Adaptor plate and assembled replacement alarm tested and approved by TÜV Austria
  • Complies with BS 5839-6: 2019 Grade D2 requirements
  • An interlinked system provides the earliest possible warning of fire
  • Replaceable 9V alkaline backup battery
  • 3 year manufacturer warranty

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

Please Note: We recommend replacing all alarms in the system together to maintain optimum system operation; failing to do so may compromise interlink performance.

Customer Reviews

Customer Reviews (109)

4.9 out of 5 stars

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

Reviewed by

H N

Published on

22nd April 2026

It clicked in and worked as described. Happy with this product

Rating: 4 / 5

Reviewed by

M T

Published on

12th April 2026

I used the SBBRKSM to replace DETA 1111. This is a very good, easy to install product, however, with the original base DETA 1111 base plate plus the 2 layers of SBBRKSM the whole alarm is quite bulky.

Rating: 4 / 5

Reviewed by

D S

Published on

10th April 2026

No problems fitting your replacement to my old mains fitting. The unit is a bit bigger than previous one that I had and hangs down a bit but all working fine.

Rating: 5 / 5

Reviewed by

D C

Published on

8th April 2026

Great replacement and very easy to fit

Rating: 5 / 5

Reviewed by

A R

Published on

5th April 2026

Perfect - exactly as described

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Technical Data

Technical Data

Product Code SBBRKSM
Brand easichange
Back-Up Battery Type Alkaline
Battery Type 9V Battery
Alkaline
British Standard Grade Grade D2: Mains Powered (replaceable backup)
Colour White
Approvals & Markings CE Marked
UKCA Marked
Compliance BS EN 14604: 2005
Connection Wired
Display LED Indicators
Fixing Options Screws (included)
Installation Position Ceiling
Material Plastic
Maximum Number of Linked Devices 12 Devices
Operating Temperature 0°C To +40°C
Positioning Bedrooms
Hallways
Living Rooms
Power Type Mains Powered (230V)
Recyclable Yes - Valpak's WEEE Distributor Take-back Scheme
Relative Humidity Up To 93%
Sensor Type Optical
Sound Level 85dB
Suitability Home
Warning Type Audible - Alarm Sounder
Warranty 3 Years
Dimensions (Unit)
  • Height: 65mm
  • Diameter: 140mm
Weight 500g
Datasheets
Installation

Installation

The simple installation process of the easichange® replacement kits, described below, negates 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.

Installation Steps

  1. Turn off the power at your fuse box or consumer unit.
    • Take care to turn off all circuits powering any of your alarms, as the interlink wire can carry a live electric current.
  2. Remove your old BRK smoke or heat alarm from its baseplate by twisting and the unplugging the connector.
  3. Insert the supplied 9V battery into your easichange® replacement alarm and close the unit securely.
    • Test the alarm to make sure it is powered up from the backup battery!
  4. Install the alarm on your old BRK baseplate:
    • Connect the plug so that the wires of the connector line up with the pins on the alarm.
    • Twist the alarm fully onto the baseplate.
  5. Repeat steps 2 to 4 for all of your old BRK alarms.
    • We recommend replacing all alarms in the system together to maintain optimum system operation; failing to do so may compromise interlink performance.
  6. Turn the power back on at the fuse box.
  7. Test each of your smoke alarms separately to ensure the whole system is functioning correctly. When you test one alarm, they should all sound, however it is important to press the test button on each alarm too.
Compatible Alarms

Compatible Alarms

It is important to select the correct easichange® alarm to replace your obsolete BRK models. The table below will help you select the correct replacement alarm. Please note that you can replace your existing BRK optical and ionisation alarms with an easichange optical alarm, however your BRK heat alarm can only be replaced with an easichange heat alarm. Please see for assistance in determining your model.

Please Note: We recommend replacing all alarms in the system together to maintain optimum system operation; failing to do so may compromise interlink performance.

BRK Model

Alarm Type

Base Type

Easichange® Replacement

660MBX

Smoke, Optical, Alkaline backup battery

Twist

SBBRKSM

670MBX

Smoke, Ionisation, Alkaline backup battery

Twist

690MBX

Heat, Alkaline backup battery

Twist

SBBRKHE