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Alarm questions answered

With new legislation fast approaching, our experts tackle some of the common queries about installing heat, smoke and carbon monoxide detectors

Q: Do I have to provide residual current device (RCD) protection for the circuit I am installing to supply a mains-powered fire detection and fire alarm system? The supply for the smoke alarms and heat detector is being taken from a local light switch and wiring is PVC sheathed (flat twin and earth), installed in a designated zone in the wall at a depth of less than 50mm from the surface.

A: Yes, an RCD with residual operating current not exceeding 30mA should be provided for additional protection as required by Regulation 522.6.202. Regulation 411.3.4 may also be applicable and should be considered. This regulation requires additional protection to be provided by an RCD with a residual operating current not exceeding 30mA for AC final circuits supplying luminaires.

Q: I am installing a fire detection and fire alarm system in an existing owner-occupied flat. Which grade of system would be recommended and why?

A: When installing a mains-powered fire detection and fire alarm system in an existing owner-occupied flat, the minimum grade and category recommended in BS 5839-6 is a Grade F2 LD3 system. However, Note G to Table 1 in the standard advises that in Scotland the minimum required by the Tolerable Standard is a Grade F1 Category LD2 system. Note that the installation of a mains-powered fire alarm system in a flat – classified as Schedule 3 work – normally requires to be carried out under the scope of a building warrant and BSD TH handbooks recommend the equivalent of at least a Grade D2 Category LD2 system for compliance. Also note that the Scottish Government fact sheet, Fire and smoke alarms: Changes to the law, advises that in some instance if the homeowner prefers for a battery-powered system to be installed, e.g. to prevent damage and upheaval to the fabric of their property, this may be acceptable to the local authority verifier if being installed as part of work associated with a building warrant for an alteration, conversion or extension. The homeowner should, however, have obtained the local authority verifier’s agreement for this prior to arranging for the work to be carried out. This type of installation will also satisfy the minimum requirements of the Tolerable Standard provided the battery-powered alarms are radio frequency (RF) linked alarms installed as per Scottish Government guidance. Note also that the installation of a battery-powered fire detection and fire alarm system can be carried out without requiring a building warrant in such instances.

Q: What certification should be provided following the installation of a mains-powered fire detection and fire alarm system in a dwelling?

A: BS 5839-6:2019 is the code of practice for the design, installation, commissioning and maintenance of fire detection and fire alarm systems in domestic premises. It recommends that for mains-powered Grade D systems, certification as provided in Annex E of the standard is provided to the user. Annex E provides a model, Certificate for design, installation and commissioning of fire detection and fire alarms and a certificate based on this should be issued on completion of work. Note that when installing a mains-powered system, compliance with BS 7671: 2018 (as amended) Requirement for Electrical Installations is also required. An Electrical Installation Certificate (EIC) or Minor Electrical Installation Works Certificates (MEIWC) as relevant should be issued to the person ordering the work. Also, don’t forget to provide operation and testing instructions for the system and hand over any user manuals together with the certification.

Q: What certification should be provided following the installation of a battery-powered fire detection and fire alarm system in a dwelling?

A: BS 5839-6:2019 recommends that for battery-powered Grade F systems, certification as provided in Annex E is given to the user when installed by a professional installer, e.g. an electrical contractor. Where a battery-powered Grade F system is installed by the user, landlord or fire and rescue service, certification is not necessary for the purpose of conformity to BS 5839-6. It is worth noting, however, that where a solid interlink is used in a Grade F1/F2 system then that wiring would mean that the system would come under the requirements of BS 7671 for certification.

Q: What certification should be provided following the installation of a mains-powered or battery-powered CO alarm?

A: There is no specific certification requirement given for this in the standard BS EN 50292:2013 guide. However, a CO alarm that is mains-powered will require the supply to it to be verified as being compliant with BS 7671:2018. An EIC or MEIWC as relevant for the circuit that supplies the alarms should be provided, together with operation and testing instructions and any user manual. Note that the CO alarm should make a different sound to that produced by the fire detection and fire alarms to differentiate it from these alarms as outlined in Clause 13.2 of BS 5839-6.

To find out more and access Member resources visit the SELECT website.



Q: Customers have asked whether not installing a satisfactory fire detection and fire alarm system will affect their home insurance. What should I advise?

A: This is still a grey area. However, we are currently recommending that Members should advise customers that it will depend on the terms and conditions of their individual home insurance policies. Homeowners should always contact their insurer to check if the new rules are included in their policy. Please note that an informative note to BS 5839-6 advises that since Grade F systems are only suitable for installation in existing single-family dwellings of no more than two storeys, a certificate of conformity to BS 5839-6 is not normally required by any enforcing authority and is unlikely to be required by a fire insurer.



Q: I am quoting to install a fire detection and fire alarm system for a customer, but they are querying the price, saying that the Scottish Government said it would only cost £220. What should I tell them?

A: The figure given by the Scottish Government was only ever provided as an example of the cost for a self-installed interlinked battery-powered system in a two-storey house. Obviously, the costs associated with the installation of a fire detection and fire alarm system to comply with the Tolerable Standard will vary depending on the grade and category of system to be installed and the type and make of alarms to be installed, i.e. a mains-powered system that is installed by a qualified electrician is likely to cost more than a battery-powered system installed by the homeowner!

Q: My customers say they just want the cheapest option as long as it meets the new standard. Is this, OK?

A: We all know that customers are often driven by cost and yes, a mains-powered fire detection and fire alarm system always provides a higher reliability system than a battery-powered system and is the best option. However, guidance on what is deemed acceptable for compliance with the new legislation does allow for battery-powered systems and is acceptable.



Q: A customer told me they have had someone coming to their door offering to install the alarms for them. What should we tell them?

A: Unfortunately, there are plenty of unskilled and unscrupulous people out there looking to take advantage of the introduction of new legislation. Our advice would be to always use the services of an accredited installer such as a SELECT Member who is accredited in SELECT Work Category 3.3 – Fire Detection and Fire Alarm Systems in Dwellings – and who should be able to advise on design, installation and commissioning and provide required certification.



SELECT’s view is that only suitably competent persons should be installing fire detection and fire alarm systems in Scottish homes.

SELECT Members accredited in Work Category 3.3 are assessed as being suitably competent to carry out fire detection and fire alarm work to BS 5839-6 and will also be familiar with the requirements and guidance for compliance with the new legislation being introduced under the Tolerable Standard.

Where undertaking such work under the scope of a building warrant, it should also be noted that Approved Bodies and Approved Certifiers of Construction registered in SELECTs Certification of Construction Scheme will also have the necessary competence to undertake and certify such work.

Knowledge of relevant legislation, standards and quality manufacturer products is paramount to ensure the fire safety of all residents in Scottish homes.




A two-minute information film, designed to be shared online and across social media platforms, educating the public on what they should do next and reminding them to use a SELECT Member to carry out any electrical work.


Three free downloadable guides, one giving an overview for the public, the others providing more technical in-depth advice for Members. Print copies of all three brochures are available by emailing:


SELECT has created a downloadable image for Members to use on their website or social media business page, along with an example message explaining why the public should always use a SELECT Member to install and test their system.


Details of the free CPD accredited training scheme from Aico, which provides electrical contractors with the latest requirements and information to select, site, install and maintain Aico alarms to the highest quality.


Details of where to obtain certificates of design, installation and commissioning that can be given to clients to show that an installation complies with the relevant standard. Certificates are available via SELECTcerts or in paper format.


A list of the most commonly-asked questions about the new standard, to help prepare Members and their clients for the changes. These will be updated in line with any changes as the 1 February 2022 deadline draws nearer.


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