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How to fit an electric door release

Updated: October 2026

How to fit an electric door release on a timber side door is a sequence: identify the supply, offer the body up, cut only the timber it needs, and connect low voltage. UK reviews in the [electric door release comparison](/hub/door-and-window-security/electric-door-release) say instructions are missing and polarity is unmarked. If voltage and fail mode are still guesses, use the [electric door release buying guide](/hub/door-and-window-security/electric-door-release/sub/electric-door-release-buying-guide). Peter F. used those notes on 19 October 2026. There was no lab test. A purchase through our links can earn a commission at no extra cost to you.

How to fit an electric door release on a timber side door is a sequence: identify the supply, offer the body up, cut only the timber it needs, and connect low voltage.

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 secure 24 V

Rank 2

AMALOCKS SecureMyDoor fail secure 24 V
7.6/10about £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.Before any chisel
  2. 2.Frame, cable and jaw
  3. 3.What the reviews found when the box was thin
  4. 4.When you stop

Before any chisel

Fit only after the coil voltage matches the supply. Meter the pair that feeds the old keep. UK mains are 230 V with a BS 1363 plug on the supply, not on the strike. If you cannot tell low voltage from mains, stop. Offer the new body up before you remove timber. The effeff 118E, the best value only when the plate is already there, does not include a strike plate. Confirm the meter reading sits inside 10–24 V before that body is screwed home. Do not copy another maker’s 1 mm gap onto these units.

Frame, cable and jaw

You cut the frame, not the door. One apartment review of the top pick and one side-gate review had to chisel because the new body was larger. Mark that extra and take out only that timber. A steel frame or a certified fire door is no longer a household chisel job. Keep the cable out from under the plate. With 12 V or 24 V DC confirmed, operate the handset, then pull the low-voltage fuse. A fail-secure jaw stays locked. A fail-safe jaw can be pushed. Nothing on these listings describes a jumper that converts the mode.
effeff effeff 118E door opener

Testsieger

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

What the reviews found when the box was thin

Reviews of the 24 V unit say polarity is unmarked. If the jaw does not move and 24 V is present, isolate the supply, swap the two low-voltage cores once, and try again. If it still does not move, stop. One review wrote that 12 V was not enough. A Yale-type sprung bolt can relatch. A mortice deadbolt cannot. Check the packet for frame screws before the old keep comes out. Named picks are on best electric door release.

When you stop

Stop if the door is a fire door, a stair exit, or the release has to drop on a fire-alarm relay. Approved Document B and BS 7273-4 are on electric door release on a fire door. Stop if you cannot identify the supply as 12 V or 24 V DC. A 230 V connection is not a test. The household sequence ends when the low-voltage jaw test matches the listing.

Common questions

Do I cut the door or the frame?
Cut the frame, where the keep sits, and only after the new body has been offered up to the old pocket. The door edge stays as it is unless a locksmith is changing the lock as well. One apartment fit and one gate fit in this set needed extra timber removed because the new body was larger. Mark that extra from the body. Do not open the cut-out to be safe and then pack it with filler.
How do I know the supply is 12 V DC and not mains?
Read the power-supply label or meter the output that feeds the old keep. Door-entry coils in this set are 12 V or 24 V, or 10–24 V on the effeff listing. The 230 V side stops at the supply’s mains input. If the cores are unmarked and the label is missing, do not connect the new coil. Call an electrician. A review of the 24 V unit said 12 V was not enough. That is a low-voltage mismatch, not a reason to try mains.
Which way is positive if the coil is unmarked?
The 24 V reviews say polarity is unmarked and there are no instructions. This page will not invent a colour code. Isolate the supply, confirm 24 V DC, and if the jaw does not move, swap the two low-voltage cores once. If it still fails, stop. Reversing the cores on a 12 V supply will not make a 24 V coil work.
Why will a mortice lock not lock again when the door shuts?
A mortice deadbolt does not throw itself. A review of the 24 V SecureMyDoor unit said a Yale-type sprung bolt closed again after the jaw opened, and a mortice deadbolt did not. The release frees a bolt. It does not turn a key. If the door must relock on the shut, the latch has to be the sprung type, or you still throw the deadbolt by hand.
When do I stop and call a locksmith?
Stop if the door is a fire door, an escape stair or a common corridor, if the release must drop on a fire-alarm relay, or if you cannot identify the supply as 12 V or 24 V DC. A steel frame, a closer or a seal you do not understand is the same stop. A 230 V connection is not a test. The household job ends when the low-voltage jaw test matches the listing.

Related pages

Fail safe vs fail secure 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)