Mains Smoke Alarms

Grade D1 mains-powered smoke alarms come with a tamper-proof backup battery lasting the full life of the alarm, making them the recommended choice for rental properties. Grade D2 alarms have a user-replaceable backup battery and are generally more suitable for owner-occupied homes, as set out in BS 5839-6.

They are a legal requirement for new residential builds and extensions under Building Regulations Approved Document B. Welsh landlord regulations specifically require mains-powered interlinked alarms in all rented homes. In Scotland, alarms must either be mains powered or fitted with a tamper-proof battery.

They are smoke alarms hardwired into a building's 230V electrical circuit, with a backup battery in case of power failure. They are the required standard for new builds, extensions and most rental properties in the UK, meeting BS 5839-6 Grade D requirements under current building regulations.

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.

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.

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.

A mains smoke alarm is more reliable than battery models because it receives continuous power from the electrical supply, eliminating the risk of power failure due to dead batteries.

Most mains smoke alarms incorporate backup batteries to maintain protection during power cuts, ensuring continuous fire detection even when the electrical supply fails.

Upgrading to mains smoke alarms requires an electrician to connect the units to your home's electrical circuit, which cannot be done as a simple replacement of battery units.

The lifespan of mains smoke alarms is typically 10 years for the detection sensors, though the electrical components may last longer with proper maintenance and testing.

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.

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.

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.

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

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.

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.

Related videos:

• How to radio-interlink the Ei3100RF series smoke alarms

• How to radio-interlink the Firehawk W Series smoke and heat alarms

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.

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.