Smoke Alarm FAQs

Mains powered alarms should be fitted by qualified electricians and can either be wired directly from your fuse board or via the pre-existing lighting circuit. This should comprise of a minimum of 2-core earth cable to the first unit. For the connection between the alarms a 3-core earth cable would be required.

It is possible to purchase replacement or additional keys for the exitguard. These will come direct from the manufacturer; you will need to provide us with your proof of purchase from us and we would be able to contact the manufacturer for you.

The EI600RF series is the latest model from EI / Aico that builds upon all the features of the Ei3100RF. The EI600 series smoke alarms come equipped with a sealed lithium battery offering a ten-year lifespan, making them suitable for use in most scenarios as a BS5839 Part 6 Grade D system.

The EI3016 would be suitable for your requirements. The kit is supplied with a new mains powered smoke alarm and with or without a specially designed masking plate that will cover any discolouration or blemishes left behind by your old alarm.

Yes, we have the Easichange tool available to purchase separately. We also sell the 9v lithium longlife back up batteries required for many mains powered alarms.

The replacement alarm uses the more modern optical sensor technology, making it less likely to false alarm, than the older ionisation technology. The alarm will also interlink with any other EI140/140RC alarms remaining in your system. Additionally, the new alarm head will fit on the existing base plate meaning you will not need the services of an electrician to install the new unit.

All our mains powered smoke alarms come from reputable manufacturers, we ensure that they conform to the relevant standards. Ensure that the alarms you purchase are correct for your home and meet the legislation for the country the property is in.

A number of our mains powered smoke and heat alarms now are available with replacement heads, meaning that you will be able to change the alarm without needing to employ the services of an electrician. We also have a range of heads that will fit on the bases of discontinued alarms.

You cannot alter the sensitivity of your alarm. However, it is recommended that you install a heat alarm in the kitchen. These are unlikely to false alarm from cooking, they will sound once the unit detects heat of 58°C. Heat alarms are ideal for use in kitchens and garages, where the use of optical alarms would lead to unwanted nuisance alarms.

Yes, we have a system of alarms from Hispec. They contain smoke, heat, and a CO alarm, giving your home full protection from the dangers of smoke and CO. The kit contains a vibrating pad and a strobe light on a central control unit, if smoke or CO are detected. The strobe will flash and the pad will vibrate to alert the user, even if they are asleep. The LED display on the control unit will show what danger is present allowing the occupant to act accordingly.

With all radio interlinked alarms you will need to link them together so that they can ‘talk’ to each other. There are slightly different processes to complete in order to do this depending on the make and model of the alarms that you have purchased. The instructions will be in the user manual and you should do this prior to fixing them to the ceiling.

A replacement is available for the EI151 which will interlink with any other Ei150 alarms in the series. The Ei3016 uses optical sensor technology that is less likely to false alarm compared to the ionisation technology of the Ei151. However, it will not fit on to the existing base and an electrician would be required to install the new unit. We also supply a masking plate Ei1516 to cover any holes in the ceiling caused by the old alarm.

There are many ranges of alarms that can interlink with a CO alarm, this gives all occupants the earliest warning of danger whether it is from smoke or CO. The alarms will have a different tone for the danger present so you can take the appropriate action.

No there are not different alarm sounds to differentiate between smoke and heat alarms, when interconnected alarms are triggered. Assuming there is no fire present, you will be able to tell which alarm was set off first by looking out for a rapidly flashing red LED, some systems the first alarm will still sound until it has been located and the hush button pressed on this unit.

Yes, it doesn’t matter which call point is activated, all linked alarms in the series will sound giving occupants the earliest warning of danger. Call points in larger buildings are especially useful as they are manually activated by the person discovering a fire which may be minutes before the smoke triggers an alarm providing more time for residents to get to safety.

If one alarm in a series of radio-interlinked alarms were to fail due to a fault or the battery needing replacement then the other alarms in the series would still work together. It is recommended that you install new batteries or replace the faulty / non-operational alarm as soon as possible so that your home has complete cover should there be a fire.

All of our radio interlinked smoke and heat alarms would be suitable. As the name suggests they do not need to be connected together via wire, minimising any damage to your ceilings. You also have the option to have a sticky pad or magnetic pad to affix the alarm to the ceiling instead of needing to drill into the ceiling.

Yes this is possible. We have a number of manufacturers that have mains powered alarms that can also be radio interlinked to battery powered alarms in the same series. For example, the FireAngel Pro Connected Series. It is important to ensure that all the alarms in your how meet the correct grade under BS 5839-6 as a mixed system may not be permitted in your property.

Yes, there are smoke and CO alarms that have been tested to make sure they are suitable to be installed in motorhomes, caravans, boats and for travel in general. For smoke alarms look out for those alarms tested to BS EN 14604:2005 and for carbon monoxide detectors make sure it has been tested to BS EN 50291-2.

We recommend testing alarms weekly by pressing the test button built-in to the unit, as this is designed to simulate the detection of the target stimuli (usually smoke, heat, or CO) at the alarm sensor. For more detailed guidance, check the manual included with your alarm.

Do not attempt to test the alarm by using open fire or excessive heat as this may damage the unit and invalidate the warranty.

Unfortunately yes, the label states that the contents are extremely flammable.

The Ei600 series does not conform to Grade D, it conforms to Grade F, relating to battery operated interlinking smoke detection. Grade D systems relates to mains powered interlinking alarm systems.

Smoke alarms can be either screwed to the ceiling using the holes on the base plate (screws provided), or fixed in place using either a self-adhesive sticky pad or a self-adhesive magnetic mounting kit.

To ensure your smoke alarm is functioning properly, it's essential to test it regularly.

Steps to Test a Smoke Alarm

1. Check the Date: Ensure the smoke alarm is not older than 10 years. If it is, replace it.
2. Press the Test Button: Locate the test button on the smoke alarm. Press and hold it for a few seconds. You should hear a loud alarm sound, indicating that the unit is working. DO NOT USE REAL FIRE, VAPES, OR CIGARETTES TO TEST SMOKE ALARMS. This can damage the smoke alarm and void any warranty. For more detailed guidance, please consult the manual provided with your smoke alarm.
3. Clean the Alarm: Dust and debris can affect the alarm's performance. Use a vacuum cleaner with a soft brush attachment to clean the outside and inside of the alarm.
4. Document the Test: Keep a record of when you tested the alarm and any maintenance performed. This helps ensure regular checks.

Frequency of Testing

• Monthly: Test the smoke alarm every month.
• Annually: Clean your alarm. If your alarm is sounding a low battery warning, replace the batteries.
• Every 10 Years: Replace the entire smoke alarm unit.

Regular testing and maintenance of your smoke alarm can significantly enhance your safety and preparedness in case of a fire.

Sign up to our free smoke alarm reminder service to receive regular reminders by email or text message.

When in the "collapsed" position, the NCSOLO100 poles measure approx. 1.26m. When fully extended they will give a maximum reach of 4.5m in 4 sections for access up to approx. 6.00m

The radioLINK repeater function allows the smoke alarm to "repeat" the radio frequency signal around obstructions. This stops the signal from becoming blocked and ensures that all interlinked alarms can be reached. This repeater function is built-in to the the Ei168RC radioLINK base (with Ei140, Ei160 or Ei2110 alarm), the Ei600 series of radio interlinked battery powered smoke and heat alarms as well as the Ei262 and Ei208WRF carbon monoxide alarms as standard. When house coded, the system works itself out which alarms are to act as repeaters - it's not something you set up yourself.

Each manufacturer of alarms has a slightly different ways of linking the alarms together, so it always recommended that you read the user manual and understand the process before beginning. We have a number of videos that will also help guide you visually through the interlinking process.

There are different ways to access the battery compartment depending on the make and model of the alarm. It is always advisable to check the user manual before trying to change the batteries. Many alarms have slide off battery covers that you would commonly see on other devices that take batteries, some you need to find the arrow on the side of the alarm, then pull the lid off the base in the same direction as the arrow. Most, just need twisting off the base plate and the battery will be on the underside of the head unit.

Yes, depending on your current alarm setup various manufacturers provide additional strobes for their systems, such as Hispec deaf aid kit, it would be particularly useful to have one in the bedroom and one in the room where they spend most of their time during the day for added safety for the occupier. You can also add additional strobes and vibrating pads to the EI range of alarms.

Manufacturers of alarms will periodically discontinue certain alarms, or even entire ranges of alarms. Usually, because technology has advanced and the new alarms are better than their predecessors. Most often they will be backwards compatible, meaning that they will still work with the existing system you have in place. We have a dedicated list of alarms that can be used as direct replacements, we also include alarms that will fit on the existing base plate. This is especially useful if you have a mains powered or radio interlinked system.

No this is not possible, 10 year sealed lithium batteries are non-replaceable and you should not attempt to gain access to the battery inside this kind of smoke or heat alarm. Also, it is worth noting that for all smoke and heat alarms they have a lifespan of 10 years and should be replaced after this date as they may not operate as they should, meaning they may not sound in the event of a fire.

Smoke alarms are more likely to ‘chirp’ at night due to lower temperatures.

The voltage of a battery drops as it reaches the end of its life. When a smoke alarm detects this lowered voltage, it emits a regular beeping sound before the battery finally expires, providing sufficient time to replace the battery before the alarm is deactivated.

Lower temperatures can also cause the voltage of a battery to drop. Our houses are often cooler at night, causing the voltage to drop, which triggers the low battery alert. It is particularly common in autumn and winter.

The Ei140 series has a small rectangular hole in the side of the unit. To remove the head of the unit you need to:

1. Disconnect the mains from the unit at the fusebox
2. Insert a small flat head screwdriver in to that hole
3. Press down slightly with the screwdriver and slide the head in the direction of the arrow. This should slide off with ease. If not a little pressure may be needed to be able to slide it in the direction of the arrow.

There is also a video to demonstrate how to remove your alarm and change the battery on the website.

Yes, during normal functioning the alarms do have an LED light that flashes every 40 seconds, this is to show that the alarm is in operational mode.

We now have the Ei154EK which is an Easichange Kit. These Easichange kits comprise of a new unit head, an Easichange tool, a ten year Lithium battery and detailed instructions on how to safely change the units without the need for an electrician. The tool provided allows you to easily remove the head of the existing unit and replace it with the new head. As the base is not being disconnected, no electrician is required.

On average you should get around 200 uses out of the 150ml can and 300 uses out of the 250ml can. However, a number of factors should be taken into account; ensure that the canister has been stored within its optimal temperature range, the length of time the nozzle has been held down for, the ambient temperature in the room where the testing is taking place all of these factors can have an effect on how much of the aerosol is used during a test.

It is not recommended to have a smoke alarm in or near a kitchen due to the likelihood of false alarms from cooking. A heat detector should be installed in a kitchen, as it is activated once temperature inside the room reaches approx. 57°C, therefore, it does not sound falsely when cooking fumes are present. When installing a heat detector, please note that this should be fitted centrally in the room and not directly above any cooking appliances.

In order to add a new alarm to an existing system you will need to repeat the pairing process. This will be in the user manual instructions, as it will be model specific. Always ensure that you test the alarms to ensure this has worked before replacing them back on their base plates.

For mains powered 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 alarms with a standard alkaline back up battery, the battery would last up to a year without mains supply. If you have a mains powered alarm with a sealed longlife lithium back up battery this should last the remaining life time of the alarm.

There are a number of alarms that we sell that are recommended by the Fire Service. When purchasing any alarm, it is important to make sure that it meets the most recent British Standards. For example, Smoke alarms should be certified to BS EN 14604: 2005, Heat alarms should be certified to BS 5446-2: 2003 and CO alarms BS EN 50291-1 this ensures you get a quality product that has been extensively tested.

Mains powered alarms are wired directly into the wiring circuit of your home, which has constant power. Therefore, will not be affected by any switches or dimmers.

With all alarms that have a sealed battery there may still be some residual power in the battery even when removed from the base plate. The alarm should stop chirping after 5 - 10 minutes, after this it can be disposed of either using the Valpak’s WEEE distributor take-back scheme or by taking to your nearest battery recycling point.

It is recommended that any mains powered alarms are installed in your property by a qualified electrician. In general, when wiring alarms correctly from the nearest light fitting you would use 2 core wire. Please always check the user manual for the wiring diagram for the range of alarms you wish to be installed.

The sticky pad is suitable for all battery operated smoke alarms. However, we cannot judge if battery alarms are suitable for your let property, as let properties usually require mains powered alarms. There is some advice to this in the governments guides to fire risk assessments. Also see the LACoRS guide for let properties.

If your smoke alarm is sounding continuously, first check there is no smoke or fire in your property. If no fire or smoke is present, or the alarm is beeping intermittently, there are three main reasons why this may be happening:

• It could indicate the alarm is over 10 years old and needs replacing. View our range of smoke alarms to find a replacement.
• There could be a build up of dust inside. To clean it, you can use a vacuum cleaner or hair dryer on a cold setting.
• It could also be an issue with the power supply or the batteries may need replacing.

Read our in-depth smoke alarm troubleshooting guide to find a full list of reasons and solutions.

You should replace your smoke alarm every 10 years. This is because the sensors in the alarm become less sensitive and may not activate when a fire is present.

Sign up to our smoke alarm reminder service to be reminded by text or email when your alarm is due to be replaced.

Optical smoke alarms, also known as photoelectric detectors, have a high sensitivity to large particles in the air. They are slightly quicker at detecting slow-smouldering fires that produce a lot of smoke (such as fire from soft furnishings). They are suitable for living rooms and sleeping areas and are used near kitchens as they are less prone to false alarms.

Ionisation smoke alarms use a small amount of radioactive material in the sensor chamber to detect fires, and have been discontinued. Safelincs encourages customers to purchase optical smoke alarms instead.

See also heat alarms for the most suitable protection in a kitchen.

Read more about how different smoke alarms work.

Mains-powered alarms have a battery as a backup in case the power fails. Without the backup battery, the building would be unprotected against fire while the electricity was cut off. With our mains powered alarms, you will always be protected.

The best location to install your smoke alarm is in the centre of the ceiling rather than on the wall.

During a fire, smoke initially rises and then spreads horizontally. Placing the smoke alarm in the centre of your ceiling means that it is closest to all four points of your room. This ensures that you receive the earliest possible warning of a fire.

For more information, read our guide to positioning your smoke alarm and guide to which smoke alarms are best for each room.

Yes, we sell a range of combined smoke and CO alarms which detect both fire and carbon monoxide.

We also sell combined heat and CO alarms which detect changes in temperature in a room rather than smoke. These are ideal for kitchens & garages where smoke or dust may often be present.

Safelincs has signed up to Valpak's WEEE (Waste Electrical and Electronic Equipment) Distributor Take-Back Scheme*. This means if you are a Safelincs customer you can take old smoke, heat and CO alarms to your local recycling centre.

To find your nearest recycling centre, please visit www.recycle-more.co.uk. Find out more about smoke alarm disposal.

*Registration ID: 7370

Yes, air purifiers, diffusers and steam can all cause a smoke alarm to sound falsely. To prevent this from happening, position the device as far away from smoke alarms as possible.

• 9V alkaline batteries last 12-18 months
• Lithium batteries last around 5 years (some lithium cells are also rechargeable, and when used in a mains-powered alarm may last for the entire functional lifespan of the alarm)
• Sealed lithium batteries last the lifetime of the alarm (usually 7-10 years)

Please note: the actual lifetime of your batteries depends on how often the alarms are tested or activated, as sounding the alarm draws more power than when the alarms are "waiting" to detect fire. You should also read your alarm's manual to make sure you only use the recommended types and brands of batteries, as failing to follow these instructions may cause the alarm to malfunction, not alerting you in the event of a fire, and might also invalidate the warranty.

There are a number of possibilities as to why mains-powered smoke alarms might beep after installation:

1. The fuse to which the alarm is connected has not been switched back on. This is a very common occurrence.
2. The cable connection is incorrect, resulting in the alarm not receiving mains power. If left the backup battery will get drained.
3. If the alarm is connected to a nearby lighting circuit the connection might be wired incorrectly, interrupting the power supply when the lighting is switched off.
4. Sometimes, the backup battery of a rechargeable smoke alarm takes time to reach operating level and the alarm might beep for a short time.

Smoke alarm troubleshooting guide to find a full list of reasons and solutions.

Yes, by pressing the test button on one interlinking smoke / heat alarm all the linked units will also activate. This is so you can check that all the alarms in your system are connected and working as they should. It is recommended to test your smoke / heat alarms weekly, so you are aware if there are any issues that need addressing. For example, depending on the make and model you may need to change the batteries. Also, regular cleaning of the alarm heads to ensure that the sensor chamber is free of dust and insects that may cause false alarms or chirping.

For most rooms including bedrooms, living rooms, downstairs hallways and even the loft space we recommend using optical smoke alarms. They are designed to quickly detect smoke from all sources and are particularly quick to detect smouldering fires, as well as being less prone to false alarms caused by steam and fumes created by everyday cooking and fireplaces under normal, safe circumstances.

Previously, ionisation smoke alarms were recommended for some rooms, but this older technology utilising radioactive material has been phased out of production globally in favour of optical detection.

For kitchens and garages, we recommend using heat alarms as they detect heat and not smoke, making them ideal for rooms where smoke fumes, vapours, dust, and damp are common.

Yes, we have a range of radio-interlinked smoke alarms designed to cover large houses on several floors. Our RF smoke alarm ranges interlink up to 50 smoke alarms in one system.

Generally, the process for interlinking hardwired alarms is the same. Firstly, you need to make sure that the alarms you are purchasing are compatible with each other, as alarms from different manufacturers (in most cases) do not mix. Dependent on the manufacturer's instructions, you will then be advised to use either a length of bell wire / twin cable to serve as an interlink cable, or 3-core and earth (which is usually adopted in newer installations).

In the same way as interlinking hardwired alarms, it is still crucial to check compatibility between alarms for systems that link wirelessly. The way in which radio-interlinked alarms are connected can differ from brand to brand, however, there will be instructions included with the alarm to guide you through the interlinking process. No signal cables are required between radio-interlinked alarms.

Yes, battery radio-interlinked smoke alarms are suitable to be installed in this type of property. In this type of home, you will need to check the distance of the RF signal of the smoke alarms you are considering. It is worth noting, that radio frequencies travel in all directions, so will pick up an alarm from the floor below, for example. Before attaching the alarms to the ceiling, you can test your system to ensure that each alarm will sound using the test button, if necessary, you will need to add to the system to make sure that when one alarm is triggered all alarms sound giving you the earliest warning of danger.

Batteries in radio-interlinked alarms tend to expire quicker than in standalone units as they are regularly sending and receiving signals from other units in the network, therefore, reducing the lifespan of the batteries. If you opt for a sealed long-life battery then these would last the lifetime of the alarm.

Most radio-interlinked alarms have a range of 100 metres in an open space and up to 30 metres in buildings. However, this can be affected by the thickness of walls and the distance between each alarm as they act like a relay to ensure all alarms are triggered in the event of a fire.

In some circumstances you are able to mix a fire alarm panel with domestic alarms. These are usually in shops with flats above or HMO’s where there is a panel system covering the communal areas and domestic alarms in the residents’ rooms. You should always check with a Fire Risk Assessor to make sure this type of system is compliant for your circumstances. You can install mains powered radio-interlinked alarms in the rooms and a mains powered alarm with an Ei128R base near the central control panel. The Ei128R base would then be connected with wire to the panel, this means that is one alarm is triggered then all alarms are, giving all residents the earliest warning of danger.

We recommend long-life battery-powered smoke alarms for B&Bs as they contain 10-year lithium batteries, which last the full life of the detector. We also offer a radio-interlinked option so that if one alarm detects a fire, all connected alarms go off.

Alternatively, you can install mains powered alarms which are also available with long-life backup batteries and wireless interlinking.

To cover all the usual fire types within a home it is recommended that you install a selection of radio-interlinked smoke alarms. Install optical smoke alarms in hallways, landings, living rooms and bedrooms as well as heat alarms for the kitchen and garage. It is also recommended to install a radio-interlinked carbon monoxide alarm if you have solid fuel appliances, open fires and wood burners. Multi-sensor radio-interlinked alarms use two detector types in one alarm, giving you the earliest fire warning possible. You can purchase the radio-interlinked alarms separately or as a complete home alarm kit. Our Smoke Alarm Buying Guide explains more about smoke alarm types.

We recommend using an optical smoke alarm in hallways, living rooms, dining rooms and bedrooms, as they are good at detecting smouldering fires from soft furnishings and are less likely to be set off by cooking fumes from a connected kitchen.

Heat alarms are recommended for kitchens and garages as they do not sound false alarms from cooking fumes, vehicle fumes or steam.

Ionisation alarms have been phased out due to the small amount of radioactive material used in the detector chamber. Safelincs recommends optical smoke alarms where ionisation alarms were previously used.

We recommend installing an optical smoke alarm in a bedroom with an en suite bathroom.

It would be less likely to sound a false alarm if steam or water droplets were to come into contact with the smoke alarm. They are also slightly quicker at detecting slow smouldering fires that can originate from upholstery and over-heated wiring. 

Detectors should usually be installed as central to the room as possible. However, we recommend ensuring your detector is not installed directly in the path of the bathroom door as smoke alarms are not designed for use in bathroom areas.

This depends purely on the model and manufacturer of the alarm or system you are planning to install. Some models will allow 12 to 15 alarms to connect wirelessly, whereas other newer models can interlink with up to 50 other devices.

Please view our range of Radio-Interlinked Alarm Systems.

To ensure you hear the smoke alarm when it detects a fire you should have radio-interlinked alarms. If one of the alarms detect a fire then all the other alarms in the system will sound which will greatly increase the chance of the occupant hearing the alarm.

If the occupant has a hearing impairment there are fire detection systems for the deaf and hard of hearing that feature strobe lights and vibration pads to ensure the occupant will be alerted in the event of a fire.

All mains powered alarms can be linked, usually by wire, although there are some mains powered alarms that can also interlink wirelessly. There are also a number of alarms that are battery powered but can be wirelessly interlinked so that if one alarm is triggered all the alarms sound.

Smoke and heat alarms should ideally be installed in the centre of the ceiling. See our guide to positioning smoke and heat alarms for some helpful tips. Always refer to the manufacturer manual for specific information.

To change the battery in most smoke, heat and CO alarms you need to remove the alarms from the base plate. Our helpful videos can guide you through replacing batteries in specific alarms.

The reason why your smoke alarm has a red (or green) flashing LED light can be different for each make of alarm. Check the manual for your smoke alarm to find out why; you can usually find these on the technical data tab on most of our smoke alarms.

Here are some examples of why smoke detectors periodically have a flashing red or green LED light without an alarm sounding;

• To indicate that the alarm is receiving power and is operating normally
• An end-of-life or low-battery warning
• To indicate the alarm is in hush mode or that there is a fault with the alarm

A masking plate is used to hide the footprint of an old alarm when replacing it. The plate covers any marks left by the previous unit and maintains the aesthetics of the room.

Radio-interlinked or RF smoke alarms use radio-frequency signals to communicate with each other. If one smoke alarm detects a fire, all smoke alarms within that system will receive an RF signal and trigger them to alarm.

Radio-interlinked smoke and heat alarms ensure everyone in a building will hear the fire alarm. They are often used in large houses, rental properties, and can sometimes be used small commercial premises.

Yes, hard-wired mains powered alarms can be wired to the unswitched live feed of the nearest frequently used lighting circuit.

Depending on the make and models of the alarms you have installed the following scenarios may occur. Some alarm systems will all be silenced by pressing the hush button on any of alarms. The alarm that was the first to be triggered will easily be identified by a rapidly flashing red LED. Alternatively, some alarm systems will allow all the other alarms to be hushed apart from the one that was triggered first. The allows the occupier to know immediately which alarm needs to investigated to see why it sounded.

Since February 2022 all homes in Scotland must be fitted with interlinking smoke and heat alarms. In addition carbon monoxide alarms are required if there is a carbon-fuelled appliance or flue. 
View our list of alarms suitable for the Scottish regulations.

Unfortunately, you cannot adjust the sound level of smoke alarms. However, we offer a range of smoke alarm systems for people with hearing impairments which use strobe lights and vibrating pads in conjunction with existing alarms to alert anyone hard of hearing of a fire.

All of our heat alarms have test buttons. Press the test button for about 5 seconds regularly to ensure your alarms are operating correctly.

If you wish to test the heat sensor of the alarm, our advice is to use a Solo 822 & 823 - smoke and heat detector tester or call a fire alarm servicing company.

Sign up for our free reminder service to ensure that you check your heat and smoke alarms regularly.

Yes, many manufacturers offer additional accessories which connect to existing systems to help manage them. These can include a control unit allowing you to test, locate, and silence the alarms without needing to climb up a ladder or a stool. Others will allow you to also see separate indicators for Smoke and CO so you know immediately what action to take.

Radio-interlinked smoke alarms use a radio frequency to communicate with each other, which replaces the signal cable. When the test button is pressed, or the alarm senses smoke, a radio signal is sent from that alarm to all other alarms in the system, triggering them to sound.

Yes, all mains powered radio frequency smoke alarms need connecting to the power supply.

If you are retrofitting your RF alarms the electricity supply can be taken from the nearest light fitting. In new builds, the electrician will create a dedicated electrical circuit for the alarms.

If your mains powered smoke alarms are not radio-interlinked you will also need to connect your alarms with a signal wire.