When an access-controlled door stops working, the first call usually goes to whoever installed the card readers. Often that is the wrong trade. Electric strikes and magnetic locks sit at the junction of two systems, and the thing that has failed is more often the door than the electronics attached to it.

Two Devices That Work in Opposite Ways

Understanding the difference matters because they fail differently and they fail for different reasons.

An electric strike replaces the fixed strike plate in the frame. The latch still throws as normal; the strike simply releases or holds the keeper that the latch sits against. The mechanical latch is doing the securing, and the electronics only control whether the keeper pivots.

A magnetic lock does away with the latch entirely. An electromagnet mounted on the frame holds an armature plate on the door, and the holding force comes from magnetic attraction across a flat contact surface. Nothing mechanical engages at all.

The practical consequence: a strike needs the latch to line up, and a maglock needs the two faces to meet squarely. Those are both geometry problems, and geometry is what doors lose over time.

Fail-Safe and Fail-Secure

Worth knowing because it determines what happens in a power cut. A fail-safe device unlocks when power is removed. A fail-secure device stays locked. Maglocks are inherently fail-safe, since no power means no magnetism. Strikes come in both configurations.

Which one is appropriate depends on whether the door is on an exit route, and that is not a preference, it is a requirement. Anything on an escape route has to let people out when the power is off, which is exactly why fire exit doors and their hardware are specified together rather than separately.

Why the Mechanical Side Fails First

Access control hardware is generally reliable. Doors are not. The usual sequence is that the door moves slightly, and the hardware that depends on precise alignment stops working.

The door sags. Hinge wear drops the latch edge by a few millimetres. A conventional latch tolerates that; an electric strike has a much tighter keeper and starts catching, binding or refusing to release.

The frame racks. On a maglock, the magnet and the armature must sit flat against each other. A frame that has twisted slightly means the two faces touch at one edge rather than across the whole surface, and holding force falls off sharply. The lock still energises, so it reads as working, and the door can be pulled open anyway.

The closer stops latching. This is the single most common cause of an access-control complaint, and it has nothing to do with the electronics. A door that drifts to within a few millimetres and stops never engages the strike. The log shows the door as unsecured; the cause is a hydraulic that needs adjusting.

The armature bolt loosens. Maglock armatures are deliberately mounted with a small amount of movement so they can self-align. That fastener works loose over thousands of cycles, and a rattling armature loses contact area.

Door position switches drift. The sensor that tells the system the door is closed is usually a magnetic contact. Once the door drops slightly, the contact separates sooner than it should, and the system reports a door held open while the door looks shut.

Reading the Symptom Correctly

• Buzzes but will not open. The strike is releasing and the latch is binding. Alignment, not electronics.
• Opens sometimes. Almost always mechanical. Intermittent faults that correlate with weather or time of day usually mean a door moving with temperature.
• Maglock energised but door pulls open. Contact area has been lost. Check for a loose armature or a twisted frame.
• Reports held open when it is shut. The position sensor, which means the door has dropped.
• Strike is noisy or buzzing loudly. Often an AC strike where DC was specified, or a latch resting against the keeper under pressure from a closer set too hard.

The Diagnostic That Saves the Most Time

Disable the access control and operate the door mechanically. If it latches crisply by hand and the latch lines up with the keeper cleanly, the mechanical side is sound and the problem really is electrical. If it does not, no amount of work on the electronics will fix it. This single test sorts most of these calls in under a minute, and it is the step most often skipped.

Where Doors and Electronics Have to Be Specified Together

A fair number of these problems are born at installation rather than developing later.

Retrofitting access control onto an existing door assumes the door is square, the closer is healthy and the frame is sound. On an older hollow metal door that has been clipped by a trolley, none of those may be true, and the electronics inherit the problem. Sorting the door and frame first is cheaper than diagnosing a reader that was never at fault.

The same goes for closers. A maglock does not need a latch, so the closer only has to bring the door to the magnet. A strike needs the closer to drive the latch fully home. Those are different adjustments, and a closer set for one will not serve the other.

Frequently Asked Questions

Our maglock holds but the door still rattles. Is that a problem?

Yes, and it is worth looking at. Rattle means the armature is not sitting flat, so you are getting less than the rated holding force even though everything reports normal. Usually it is the armature mounting bolt rather than the magnet.

The strike buzzes constantly. Is it failing?

Not necessarily. Some AC strikes buzz by design. Constant buzzing on a device that used to be quiet more often means the latch is pressed hard against the keeper, which points at the closer or at alignment.

Can we fit a maglock to any door?

Mechanically, most doors can take one. The real constraints are whether the door is on an exit route, what release arrangements are required, and whether the frame is flat and rigid enough for the magnet to seat. The last is the one most often discovered too late.

Why does ours only misbehave in winter?

Because doors move with temperature and buildings pressurise differently when heated. A few millimetres of seasonal movement is nothing to a conventional latch and everything to a strike keeper or a magnet face.

Who should we call, the door company or the security company?

Run the mechanical test first. If the door does not latch crisply by hand, start with the door. If it does, start with the electronics. When something has failed outright and the opening is insecure, emergency door repair secures it first and the diagnosis follows.

The Short Version

Electric strikes need the latch to line up; maglocks need two faces to meet flat. Both lose to a door that has sagged, a frame that has racked, or a closer that no longer drives the latch home. Before anyone opens a control panel, disable the access control and work the door by hand. If it does not latch crisply, the fault is mechanical, and that is where the repair belongs.