Door Hold-Open Devices and Fire Alarm Release
Fire doors only protect a building if they are closed when a fire occurs — but people prop them open for convenience all day long. Hold-open devices resolve that tension: they legitimately hold a fire door open and release it on a fire signal so the door closes and does its job. For fire alarm engineers, the key is understanding the release, the standards that govern it, and how to prove it works. This guide covers that.
The essential idea is that a held-open fire door must reliably become a closed fire door the moment there is a fire.
Who this is for
This is for competent fire alarm engineers working with door hold-open devices and their release. The experience level assumed is competent engineer. Use it for the principles; which doors release and on what signal come from the fire strategy, the cause and effect, BS 7273-4 and BS 5839-1.
What hold-open devices are
Hold-open devices — magnetic door holders, or closers with integrated hold-open — keep a fire door open for everyday use and release it on a fire signal so the door closer shuts the door. They allow doors to be held open without permanently defeating the compartmentation the fire door provides, because on fire the door returns to its protective, closed state. Their release from the fire alarm follows BS 7273-4, which covers the actuation of release mechanisms, alongside BS 5839-1 and the fire strategy.
How release works
The device is normally powered to hold the door, and a fire signal removes power so the closer shuts the door; a well-designed arrangement also releases on power failure or a relevant system fault, so a fault leaves doors closed rather than held open. This release is a defined output in the cause and effect and is a form of actuation, which is why BS 7273-4 applies to it as well as BS 5839-1. On fire, the designated doors should release and close as designed, fully and reliably.
Which doors close and when
A crucial design point is which doors release, and on what signal. On a simple strategy all held-open doors may close on any fire; on a phased or zoned strategy only doors in the affected area may close. This is decided by the fire strategy and cause and effect — not adjusted at the panel — because closing the wrong doors can impede escape, and failing to close the right ones breaks compartmentation. The arrangement follows the fire strategy, BS 7273-4 and BS 5839-1.
Servicing hold-open devices
Servicing must prove the whole chain, not just the signal. Confirm each device releases on the correct fire signal and on power failure, that the door then closes fully and latches into its frame, and that the behaviour matches the documented cause and effect. From field experience, doors that no longer close fully because of dropped closers or damaged seals, holders left disconnected after other works, and released outputs never actually proven are the recurring findings. Re-test after any cause-and-effect change and record the results.
Common points to check
Recurring issues include doors that release but do not close and latch fully, hold-open devices left disconnected, and release outputs not proven against the cause and effect. Confirming each designated door reliably closes on the correct signal is the essential check.
When not to rely on this alone
When not to use this article: do not use it to decide which doors should be held open or released for a specific building. That comes from the fire strategy, the fire risk assessment, BS 7273-4 and BS 5839-1, applied by competent professionals, alongside the door and closer standards.
Relevant standards
Release of hold-open devices is addressed by BS 7273-4 and BS 5839-1, both codes of practice, within the fire strategy; the fire doors and closers have their own product standards. The legal duty for fire precautions and safe escape in most non-domestic premises sits under the Regulatory Reform (Fire Safety) Order 2005. Separate the legal duty from the recommended methods, and always work to current editions.
Professional disclaimer
This is an educational and workflow resource for competent engineers and does not replace the current British Standards, the fire strategy, the cause and effect, or competent judgement. Verify hold-open release arrangements against current documentation.
Related documentation
Use this with the current BS 5839-1 and BS 7273-4, the fire strategy and cause and effect, and the door and closer documentation. Record which doors release, the signals that release them, and full-closure test results, and re-prove after any change.