Smoke alarms that beep in the night – a new help guide

Ei156TLH Mains Powered Optical Smoke AlarmMains powered smoke alarms are required whenever a new home is built, a home is extended or materially altered. As they are interlinked they ensure that the alarm is spread through the entire building, notifying you of the fire even when you are in bed. Most mains powered alarms have a back-up battery inside to ensure that the alarms work even if their power supply is interrupted, for example by a blown fuse, which can happen when the fire was started by an electrical fault. Over the years, should either the power supply fail or should the backup battery become flat, the alarms will beep to notify you that there is a problem. As the cold of a night will weaken the backup battery, the warning beeps will usually start at night, which is, of course, a nuisance. However, beeping due to low battery is not the only reason an alarm might beep for and it can be very difficult to work out what has gone wrong. To help our customers, we have therefore created a simple-to-follow help guide for one manufacturer’s products. The reason for picking Ei Electronics’ products is that they are the undisputed market leader in mains powered alarms. Their smoke alarms are found in almost every new or converted home in the UK, so that we focused on their products in this help guide.

Their mains powered smoke alarm series is ‘Aico’ branded and follows the following numbering system

Ei140 series (mains powered with alkaline backup battery which needs changing every year or two)

Ei160 series (mains powered with sealed-in, rechargeable 10 year lithium battery


Within each series, there are three types of detectors ending each with one of the following numbers:

..1 (eg Ei141): Ionisation smoke alarms. Good for fast flaming fires, such as paper and wood. They do, however, have a tendency to false alarm if for example a toast is burned nearby.

..4 (eg Ei144): Heat alarms. Used in kitchens, as these units are insensitive to burnt toast

..6 (eg Ei146): Optical smoke alarms. Less prone to false alarms from burnt toast. Good for smouldering fires such as from soft furnishing

Further helpful information about smoke alarms can be found in our help section.

Replacement smoke alarms can be easily identified on our overview chart showing older smoke alarms models and their replacements.

For Aico/Ei Electronics mains powered smoke alarms we are able to offer dedicated replacement alarms that can be fitted by a home owner without requiring an electrician.

We also offer very detailed further advise about smoke alarm defects and solutions on our forum.

There is also a range of videos showing you step-by-spep how to remove smoke alarms from their bases

Extending Ei140 + Ei160 series smoke alarm groups

Many homes and small businesses are equipped with mains powered smoke alarms to BS5839 part 6 Grade D. These alarms are usually linked with cable and have to be installed by electricians. When increasing the number of smoke and heat alarms at a later date, it is costly and disruptive to run extra cable to the additional alarms, decorations are damaged and dust is created.

With the Aico Ei140 series (Ei141, Ei144, Ei146) and the Aico Ei160 series (Ei161, Ei164, Ei166), adding more smoke alarms to the group of alarms can be very simple using radio-interlinking.

Just one existing smoke alarm is taken off the ceiling and its existing base plate replaced with the RF base plate Ei168. This exchange, while very swift and simple, should be carried out by an electrician. The old alarm then simply slots onto the newly fitted base plate. Now you can install any of the radio-interlinked smoke alarm ranges from AICO/Ei in the additional rooms you wish to protect. The new radio-linked alarms will then communicate fully with the old system. This means that if any of the smoke alarms goes off (old or new alarms), the rest of the alarms will sound an alarm as well.

You have three choices to achieve this extension with radio-interlinked smoke alarms:

1) Install more mains powered alarms together with RF base plates. Their electrical power supply can be drawn from the nearest light fitting. This solution will require an electrician for all the work. However, this is a solution that will guarantee the Grade D rating of your installation. There is obviously no cabling required between the units, as the radio signal will communicate between the new alarms and, through the single converted old smoke alarm, with the old system. There are additional add-ons you can include in this system, such as RF manual break points and handheld controls for testing and, in the case of the Ei160 series, even for silencing and to locate the source of an alarm.

List of Alarms and add-ons available:

Series installed already Mains powered RF Smoke alarms available Manual break points available (optional). Wireless and 10 year battery Handheld controls available (optional)
Ei140 Ei407 Ei410TRF handheld test fob (tests interconnection, only)
Ei160 Ei407
  • Ei410 handheld test, hush and locator
  • Ei411H wall mounted test, hush and locator


2) If you want to save the cost for the electrician and want to speed up the installation process, you can install battery operated radio-interlinked alarms. One of the radio-interlinked families is the Ei600 series, which comes with a sealed-in ten year power supply. This system is usually accepted as a Grade D system, even though formally, as it does not contain mains power, it is not classified as a grade D system. If you have to satisfy a Building Inspector or the fire service, it makes therefore good sense to get their agreement before installing the system.

List of battery operated alarms and add-ons available:

Series installed already Battery operated RF smoke alarms Manual break points available (optional). Wireless and 10 year battery Handheld control (optional)
Ei140 Ei407 Ei410TRF handheld test fob (tests interconnection, only)
Ei160 Ei407
  • Ei410 handheld test, hush and locator
  • Ei411H wall mounted test, hush and locator


3) If you are not required to install in accordance to BS5839 Part 6 Grade D (eg older houses built prior to introduction of Building Regulations), you can also use radio-interlinked smoke alarms with alkaline backup batteries which must be replaced every year or two. This is of course the cheapest way of expanding your existing smoke alarm system. Again, all alarms will go off together, both the new as well as the old alarms.

List of radio-interlinked, battery operated alarms and add-ons available:

Series installed already Battery operated RF smoke alarms Manual break points available (optional). Wireless and 10 year battery Handheld control (optional)
Ei140 Ei407 Ei410TRF handheld test fob (tests interconnection, only)
Ei160 Ei407 Ei410TRF handheld test fob (tests interconnection, only)

Aico Smoke and CO Alarms installed by 2010 Rotherham Ltd

Ei21ENRC Arm’s Length Management Organisation 2010 Rotherham Ltd is installing Aico Ei261ENRC mains powered Carbon Monoxide (CO) Alarms into its properties, interconnected with Aico Ei166RC Optical Smoke Alarms.

The alarms are being fitted as part of 2010 Rotherham’s capital programme.  The CO alarms are a new improvement to the tenants’ homes and are being installed in rooms where a solid fuel or an open flued appliances exists.

It was chosen to interconnect the CO and smoke alarms together due to the fact that CO alarms need to be close to the appliance most likely to produce CO fumes – often away from bedrooms – and so there is a danger that an occupant sleeping upstairs may not hear the CO alarm.

By interconnecting with the smoke alarms, all the alarms – CO and smoke – sound.  To ensure the appropriate action is then taken (which differs depending on whether it’s a CO leak or a fire), an Ei1529RC Alarm Control switch has been installed in the main hallway, which has a ‘Locate’ function that can be used to identify the source of the alarm.

Billy Brooks, Electrical Project Manager at 2010 Rotherham, comments on the choice of alarm manufacturer: “We’ve been using Aico smoke alarms for quite a long time.  Aico is one of the manufacturers to supply alarms with Lithium cells instead of batteries (as a back up to the main supply), which solved the problem of the batteries being removed.  They also gave a good guarantee, with 10 years on the Lithium cell and five on the alarm.  These were the reasons why we included Aico products into our specification.

“We started fitting the Aico CO alarms into vulnerable properties, i.e. those with solid fuel and open flued appliances and we have now included it into the specification for our Decent Homes programme.”

The Ei261ENRC CO Alarm from Aico features the latest generation electrochemical type CO sensor which automatically checks CO levels in the environment every 80 seconds.  It comes with high and low level LED indicators with a special pre alarm LED indication for detection of CO at 50ppm and a memory feature which enables the user to tell if CO has been detected during a period of absence.  The alarm also comes with a cost-saving replaceable CO sensor design and quick CO Gas test facility.

Both the Ei261ENRC CO Alarm and the Ei166RC Optical Smoke Alarm benefit from 10 year+ Lithium cell back-up supply, hush button for false alarm control, separate mains and warning LEDs, Easi-fit fixing system for reduced installation time and effort and a comprehensive 5 year guarantee.

All Aico alarms are designed and manufactured in Ireland and meet UK standards and regulations.