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Fail safe vs fail secure door release

Updated: October 2026

The power has gone off, and you need to know whether the side door is still shut. Fail safe vs fail secure door release is that question. Fail-secure stays locked in a power cut and needs power to unlock. Fail-safe unlocks when power is lost. Listings are on the [electric door release comparison](/hub/door-and-window-security/electric-door-release). Voltage and plate are in the [electric door release buying guide](/hub/door-and-window-security/electric-door-release/sub/electric-door-release-buying-guide). Peter F. compared those amazon.co.uk listings on 19 October 2026. There was no lab test. A qualifying purchase can earn a commission at no extra cost to you.

The power has gone off, and you need to know whether the side door is still shut. Fail safe vs fail secure door release is that question. Fail-secure stays locked in a power cut and needs power to unlock.

Our top picks

effeff effeff 118E door opener

Best overall

effeff effeff 118E door opener
7.0/10about £24.41
View offer
AMALOCKS SecureMyDoor fail safe 12 V

Rank 2

AMALOCKS SecureMyDoor fail safe 12 V
7.9/10about £32.97
View offer
AMALOCKS SecureMyDoor fail secure 12 V

Rank 3

AMALOCKS SecureMyDoor fail secure 12 V
8.4/10about £32.97
View offer
On this page
  1. 1.The two behaviours
  2. 2.When fail-secure
  3. 3.When fail-safe
  4. 4.The condition

The two behaviours

Power-to-unlock is fail-secure: apply power and the jaw lets the latch go. Power-to-lock is fail-safe: the coil holds the door only while it is energised. CDVI uses those definitions. A store is not an escape stair. Buzz is not proof of the mode. Unpowered, a fail-safe jaw can be pushed and a fail-secure jaw stays blocked. M1ALOCK, the top pick, remains locked if power fails. M1AUNLOCK unlocks. Both are 12 V at about £32.97. The 24 V unit is fail-secure only. Nothing on these listings says a jumper converts one into the other.

When fail-secure

Choose fail-secure for a side door or stockroom that must stay shut in a power cut, where another way out already exists. At 12 V that is M1ALOCK, about £32.97, 4.4 from 70 reviews. A reviewer said not to use it where a person’s safety is paramount. If you have metered 24 V DC, the listing is M1ALOCK-24. A review wrote that 12 V was not enough. The TIKATARER unit states the same 12 V behaviour at about £62.50. Named shortlists are on best electric door release.
effeff effeff 118E door opener

Testsieger

effeff effeff 118E door opener
7.0/10about £24.41
View offer

When fail-safe

Choose fail-safe when the door must become free if the supply fails, and you can secure it another way when the building is empty. M1AUNLOCK is about £32.97, 12 V DC, 4.6 from 18 reviews, and it unlocks if power is lost. One buyer still added a battery-backed supply. There is no 24 V fail-safe unit in this set. The effeff 118E, the best value at about £24.41, accepts 10–24 V and does not state a mode, so it is not that missing keep.

The condition

For a store that must stay shut, use fail-secure: M1ALOCK on 12 V DC, or M1ALOCK-24 only after you have metered 24 V. For a door that must release when power fails, and that is not the escape route, use M1AUNLOCK, with a plan for an empty building. Both fail if the door is the way out. On an escape route the door has to release on power loss. That limit is on electric door release on a fire door.

Common questions

What does fail-secure do in a power cut?
It stays locked. Power has to be applied to unlock the jaw. In this set that is the SecureMyDoor M1ALOCK at 12 V DC and the M1ALOCK-24 at 24 V DC, both about £32.97, plus the TIKATARER unit at about £62.50 which states the same 12 V fail-secure behaviour. With the unit on the bench and no power connected, the jaw should stay blocked. If you can push it open, it is not behaving as fail-secure.
What does fail-safe do in a power cut?
It unlocks. The door is held locked only while power is applied. In this set that stated behaviour is the SecureMyDoor M1AUNLOCK, 12 V DC, about £32.97, 4.6 from 18 reviews. Unpowered, the jaw can be pushed. A reviewer who wanted that unlock still added a battery-backed supply, because the open state is a security problem when the building is empty.
Which is safer?
Neither word is a safety rating. Fail-secure is the safer choice for a side store that must not spring open in a power cut, if people have another way out. Fail-safe is the safer choice when someone must be able to leave as soon as power is lost. On a common escape stair the English guidance covered on the fire-door page expects unlock on power loss, so a fail-secure keep is the wrong kind of safe there.
Can I swap a fail-safe unit for a fail-secure unit on the same wires?
The wires may land, and the behaviour will change. These listings do not describe a jumper that keeps the old power-cut result. M1ALOCK and M1AUNLOCK are sold as one mode each. Like-for-like means the same mode and the same voltage, not the same two colours on a different jaw. Test the new unit unpowered before you close the frame.
Which loaded listing is which mode?
M1ALOCK is 12 V fail-secure. M1AUNLOCK is 12 V fail-safe. M1ALOCK-24 is 24 V fail-secure. The TIKATARER listing is 12 V fail-secure. The effeff 118E and the AOWINHIT body do not state a mode. If people may be inside a fail-secure door when the power fails, they need another way to withdraw the latch, or the door should not have been fail-secure. That becomes the fire-door question once the door is an escape route.

Related pages

How to fit an electric door release

Electric door release

Best electric door release: mode, voltage, reviews

Electric door release buying guide: four checks first

Electric door release fire door: unlock and evidence

Sources

Public UK sources from the research digest. Listing prices and review counts were read on 19 October 2026. The CDVI GAER page is an example for a different product, not a current figure for these six listings.

  1. Approved Document B Volume 1 (England, dwellings) (retrieved 19 October 2026)
  2. BSI BS 7273-4:2015+A2:2023 (retrieved 19 October 2026)
  3. NIFRS door release note (2025) (retrieved 19 October 2026)
  4. CDVI: fail-safe and fail-secure (retrieved 19 October 2026)
  5. CDVI: guide to electronic locking (retrieved 19 October 2026)
  6. Links Integrated Systems: electronic locking for fire doors (retrieved 19 October 2026)
  7. Regulatory Reform (Fire Safety) Order 2005 (retrieved 19 October 2026)
  8. CDVI GAER-12CC (example current, not an ASIN in this set) (retrieved 19 October 2026)