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Mains Powered Optical Smoke Alarm with Lithium Back-up Battery - Ei166RC

Discontinued Product

This product has been discontinued.

alternative product

Replacement for Ei166, Ei166RC & Ei166e Smoke Alarms

  • Power: 230V mains with back-up battery
  • Back-up Battery: Self-charging lifetime battery
  • Warranty: 5 year warranty
  • Fits onto your existing Ei166 smoke alarm base
  • Fully compatible replacement for Ei166 smoke alarms
  • Improved optical sensor technology for fewer false alarms
  • Kitemarked to BS EN 14604: 2005

£51.23 inc VAT

£42.69 ex VAT

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Product Overview
Mains powered optical smoke alarm from Ei with hush button and 10 year rechargable lithium backup cells.
  • 230V Hard-wired smoke alarm
  • Available in two versions:
  • 10 year Rechargeable Lithium Cell back-up
  • 5 year warranty
  • A maximum of 12 units can be interconnected via 3 core interconnection cable
  • Other alarms that can be interconnected include:
  • Kitemarked to BS EN 14604:2005
  • Suitable for installations complying to BS 5839-6: 2013 Grade D, E and F
  • CE marked
  • Hush button for false alarm control
  • Separate mains and warning LEDs for easier identification of alarm status
  • Auto self-test feature continually monitors the sensor every 40 seconds for additional safety
  • Precision charging circuit ensures peak cell performance
  • Low battery LED display

The table below shows all the units that can interconnect with the EI166.

Alarms from the Same Series
Model Number
Type of unit
Type of interconnection
Ei161RC Ionisation Alarm Hard wire using 3 core interconnection cable
Ei164RC Heat Alarm Hard wire using 3 core interconnection cable
EI2110 Multi Sensor Smoke & Heat Alarm Hard wire using 3 core interconnection cable
Ancillary Products
Model Number
Type of unit
Type of interconnection
Y03 Multi Frequency Sounder Hard wire using 3 core interconnection cable
MCP401RC Manual Call Point Hard wire using 3 core interconnection cable
Ei1529RC Smoke alarm Locate, Hush and Remote test switch Hard wire using 3 core interconnection cable
Technical Data
Product Code

Ei166EK Replacement Detector Head Kit:  EI166RCEK

Ei166 Optical Smoke Alarm:  EI166RC

Brand EI Electronics
Back-Up Battery

Longlife Lithium

Dimensions (HxDia)


Operating Temperature

0°C to 40°C

Relative Humidity

15% to 95% Relative Humidity

Sound Output


Weight 0.32kg
Product Datasheets
FAQs (5)
Q. Can I add a CO detector to a smoke alarm system with Ei160 alarms?

Yes, even though the Ei160 series has been discontinued, the new Ei3000 series of alarms are compatible with any remaining 160s you still have. This includes the Ei3018 carbon monoxide alarm. We also recommend that you install a Ei1529RC locator switch as well which will allow you to find out whether an alarm is caused by CO gas or a fire.

Q. How do you wire in the Ei140/Ei160 series of smoke alarms?

To wire the units correctly you would use 2 core and earth cable to the first unit and 3 core and earth to the interconnected units. The alarms do not have to be earthed but a brass screw connector is provided so that the earth can be safety terminated.

Q. Can I upgrade an existing Ei140 series base with an Ei3000 series alarm?

Yes, the new Ei3000 series is fully backward compatible and will work directly with the the Ei140 series base. Both the power supply and the interlink with any remaining Ei140 alarms will continue to work with your new Ei3000 alarm.

Q. My detector does not have "RC" stated at the end of the code. What does this stand for?

The RC just refers to "Remote Control" as the unit can be fitted to a radio-frequency base for interconnection. The model hasn't changed but the manufacturers changed the product code slightly in reference to this.

Q. For mains powered Aico smoke and heat alarms, when the electricity supply fails and the back up battery takes over, please can you tell me how long the battery will last in this situation?

For mains powered Aico alarms with a new, fully charged lithium back up battery, the battery would last approx. 3-6 months without a mains supply. For mains powered Aico alarms with a standard alkaline back up battery, the battery would last up to a year without mains supply. If the alarm has been installed with an Ei168RC radio frequency base, please note that the Ei168RC back up battery would last approx 2 months if the power fails.

Customer Reviews

10 customers have 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:

Smart looking alarm that's easy to install coupled with excelent customer services.

Published on: 23rd May 2016

Rating: 5 / 5 Stars

Reviewed by:

Easy to install, great product. Connects well to older base units.

Published on: 30th January 2016

Rating: 5 / 5 Stars

Reviewed by:

Replacement of an out of date smoke alarm, easily installed.

Published on: 11th December 2015

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