An access control system is one of those things you stop thinking about the week after it's installed. Badge in, door clicks, done — until the morning the reader flashes red at the entire accounting department, the delivery door quietly stops latching, or you discover a fob belonging to someone who left eight months ago still opens the server room.
The good news: most access control problems sort into a handful of patterns, and the pattern usually tells you where the fault is before you touch anything. Some checks are safe for anyone with admin access to the software; anything involving electrified door hardware or mains power is professional territory, and we'll say so plainly each time it comes up.
First: One Door, Every Door, or One Person?
One question cuts the list down immediately:
- One person can't get in, everyone else is fine. The system and door are healthy; the problem is that person's credential or permissions. Cause 1.
- One door misbehaves for everyone. The fault lives at that door — lock hardware, wiring, reader, or alignment. Causes 2 and 3.
- Every door is down, or the software is unreachable. That's the controller, its power, or its network. Cause 4.
- Everything works, just at the wrong times. Nothing is broken — the schedules or the clock are wrong. Cause 5.
- Everything works, and that's the problem. Dead credentials still alive, held-open alarms ignored — causes 6 and 7 are the system working exactly as configured, badly.
Now the eight problems.
1. One Card or Fob Suddenly Stopped Working
What's happening: When a single credential dies while everyone else badges through happily, there are three usual suspects. The credential was deactivated — sometimes deliberately (an expiry date set a year ago and forgotten), sometimes by accident (an admin tidying the user list clicked one row too many). The credential is physically damaged — fobs and cards carry a tiny antenna inside, and one that's been through the wash or lived in a back pocket for five years can simply stop answering the reader. Or the person fell out of an access schedule: the credential is fine, but the group or time window that granted them the door changed.
Check it yourself: Look the person up in your access software. Active status? An expiry date that just passed? Still in the right access group, and does that group still include this door at this time of day? Then run the physical test: hand them a known-good spare credential with the same permissions. If the spare works, the original is damaged — issue a new one and deactivate the old. All safe, everyday admin work.
When to call: If the credential looks right, a spare doesn't work either, and only this one person is affected, something odd is going on in the permission layers — overlapping groups, a site-level restriction, an anti-passback rule holding them hostage. That's a configuration untangle, and quick work for someone who lives in these platforms.
2. One Door Won't Unlock for Anyone
What's happening: Everyone badges, the reader beeps and flashes its happy colour — and the door stays shut. When the reader accepts the credential but the door doesn't open, the decision is being made correctly and the failure is downstream: the electric strike or maglock isn't getting power, its wiring has failed, or the lock itself has died. There's a sneakier variant. Many systems use a door position switch — a small sensor telling the controller whether the door is open or closed. If it fails or drifts out of alignment, the controller can be convinced the door is already open or in fault: refusing to release, logging endless forced-door events, alarming on a door nobody touched.
Check it yourself: Listen at the door while someone badges. A click with no give usually means the lock is releasing but the door is binding — look for a warped frame, a sagging hinge, or a latch dragging on the strike plate. Total silence after a valid read means the lock isn't firing at all. Also check whether the software shows the door in fault or "held open" while it's plainly shut — that points at the position switch. Looking and listening is as far as this one safely goes.
When to call: Everything past that point. Electric strikes and maglocks run on dedicated power supplies with their own wiring, and a locked door is often part of the building's fire and exit design. Diagnosing lock power, replacing a strike, or realigning a position switch is our work — done wrong on the wrong door, the consequences go well beyond inconvenience.
3. The Door Won't Lock
What's happening: The opposite failure, and the one that should worry you more — an unlocked door protects nothing. Three common causes. First, the lock's designed behaviour: some electrified locks are built to release when power is lost, a deliberate safety choice on certain doors. If one has lost its power supply — a tripped breaker, a dead transformer, a failed backup battery — it sits unlocked and looks "broken" while doing exactly what it was designed to do. Second, alignment: doors move with seasons and slamming, and a latch that no longer meets its strike plate can't lock. Third, the door closer — the arm at the top of the door. A tired closer stops pulling the door fully shut, and a door that doesn't close can't lock. This is the most common "access control problem" we're called for that turns out to be a $200 door hardware problem.
Check it yourself: Watch the door swing shut on its own. Does it close all the way, or stop a centimetre short? Push it fully closed by hand — does it latch now? If hand pressure fixes it, your problem is the closer or alignment, not the access system. If several doors went soft at once, that points at a power issue rather than a door issue. Don't adjust closers or touch lock power yourself.
When to call: If the door closes fully and still won't lock, or several doors unlocked together. Which doors are designed to release without power — and which must never — is a life-safety design decision, and changing how a locked door behaves in a failure is strictly professional work. If a door designed to release has lost its power, treat it as urgent: until it's fixed, that door is just a door.
4. The Whole System Is Offline
What's happening: No doors responding, software unreachable, readers dark or flashing error patterns — the controller, the panel that actually makes the unlock decisions, is down. The usual causes are unglamorous: a failed power supply, a tripped breaker, someone unplugging "that beeping box" in the electrical room, or a dropped network link between software and panel. The quiet culprit worth naming is the backup battery. Most controllers carry one to ride out short outages, and those batteries have a service life of a few years. A tired one fails exactly when it's needed — the building has a two-second power blip, and a system that should have shrugged it off goes dark instead. If your system died during or right after a power event, battery age is the first suspect.
Check it yourself: Look at the controller if you can safely see it — is anything lit? Is it beeping (often a low-battery or mains-fail complaint)? If your network is down, the software may just have lost sight of a controller that's still running the doors locally — check whether doors still respond to credentials, as many do during an outage. Don't open the controller cabinet or start reseating power connections.
When to call: A dead controller, a beeping panel, or any suspicion about the backup battery. Battery replacement inside an access panel is work on mains-connected equipment, and it's also the moment to test that the battery actually carries the system — a job worth doing on a schedule rather than discovering during an outage. If the battery has never been replaced and the system is more than three or four years old, book it before it books you.
5. Access Schedules Are Firing at the Wrong Times
What's happening: The front door that should unlock at 8:00 now unlocks at 9:00. The cleaner's fob works an hour later than it used to. Nothing failed — the system's clock and your wall clock have disagreed. The classic trigger is daylight saving time: a controller with the wrong time zone, an outdated DST rule, or no time sync at all drifts an hour twice a year and stays wrong until someone notices. A controller never synced to a time source causes the subtler version, wandering minutes per month until schedules feel vaguely off. Then there are holiday calendars, which keep the office locked on a statutory holiday that falls on a Tuesday. If the calendar was never loaded — or loaded once in 2021 and never updated — the building cheerfully unlocks on Christmas morning.
Check it yourself: Compare the time in your access software against your phone, and check the time zone setting. Review the holiday calendar: does it exist, and does it include this year's dates? Correcting time, time zone, and holidays from the software is safe admin work on most platforms.
When to call: If the clock won't hold its setting, or the system has no automatic time sync at all. A properly set-up system syncs itself to a reliable time source and carries current DST rules, so this whole category can't happen. If yours drifts, fix it once, properly — an audit log is only as trustworthy as its clock, and one with wrong timestamps is worth very little on the day you need it.
6. Ex-Employees Whose Credentials Still Work
What's happening: Nothing is malfunctioning — and that's exactly the problem. Someone left in March; it's July and their fob still opens the warehouse. This is a process failure, not a technical one: offboarding lived in someone's head instead of a checklist, IT killed the email account but nobody owned the door credentials. It matters more than most technical faults on this list — an active credential held by someone with no reason to be in your building is precisely the risk the system exists to eliminate. It's the electronic version of never getting the keys back, except you paid for the ability to fix it in seconds and didn't use it.
Check it yourself: Pull the full user list and read it against your current staff list. Every name you don't recognize, every "temp," every contractor from a finished project is a question to answer. Deactivate — don't delete — anyone who shouldn't be there, so the audit history stays intact, then check recent activity on any credential you just killed. This is safe, and honestly, do it today; it costs twenty minutes.
When to call: If the audit turns up something concerning — a departed employee's credential with recent activity — or if you'd like the process fixed rather than repeated. Tying deactivation into your offboarding checklist, putting expiry dates on every contractor credential at issue time, and scheduling a recurring access review are small changes that permanently close this hole.
7. Doors Propped Open and Held-Open Alarms Nobody Hears
What's happening: The receiving door wedged open with a pallet, the smokers' door on a rock, the side entrance held for a delivery and forgotten. Most systems can raise a held-open alarm when a door stays open too long — but on many sites that alarm has cried wolf so often everyone has stopped hearing it. Alarm fatigue is the real fault: a timer set too short for how the door is actually used means dozens of false alarms a day, so the alerts get ignored, muted, or switched off. At that point a propped door — every intruder's favourite entrance, no cloned credential required — generates no reaction at all. A misadjusted position switch feeds the same fire, reporting closed doors as open until nobody trusts anything the system says.
Check it yourself: Walk the building at a busy time and count propped doors — the answer is usually humbling. In the software, check which doors have held-open alarms enabled, what the timers are, and where the alerts actually go. If they land in a log nobody reads, they may as well not exist. Removing the door wedges is free.
When to call: Tuning. The fix is timers that match how each door genuinely gets used — sixty seconds at a receiving door, fifteen at a server room — position switches verified so the alarms are trustworthy, and alerts routed somewhere a human will act, which can include a monitoring station after hours. An alarm that fires rarely and means something gets a response. That's a design job, and one of the highest-value hours you can spend on an existing system.
8. You Can't Add Users Anymore
What's happening: The system runs the doors fine, but the management side has died. Common versions: the software licence lapsed and the vendor wants a renewal nobody budgeted; the management software only ran on an ancient back-office PC that finally gave up; or the platform is proprietary and locked to the dealer who installed it — and that dealer has retired, stopped answering, or gone out of business. The doors keep obeying yesterday's rules, but you can't issue a fob to a new hire, kill one for a departure, or pull a log. A system you can't administer isn't really yours anymore — and it fails cause 6 a little worse every month.
Check it yourself: Establish what you actually have. Photograph the controller and its labels, dig out any licence paperwork or dealer invoices, and confirm whether anyone still has working admin credentials for the platform. That inventory determines the path forward, and it costs nothing.
When to call: Now, rather than after the next staffing change. This is exactly what our System Takeovers and Upgrades service exists for: we assess what's installed, and in many cases the expensive parts — readers, locks, wiring, door hardware — are perfectly good and stay. Often it's only the brains that need replacing with a platform you can actually administer, on open standards, so you're never locked to a single dealer again. Being orphaned once is bad luck; staying orphaned is a choice.
A Maintenance Rhythm That Prevents Most of This
Nearly everything above is preventable or catchable early with a light routine:
- Monthly: Walk your doors. Watch each one close and latch on its own. Note anything dragging, binding, or propped.
- Quarterly: Audit the user list against current staff and contractor lists; deactivate what shouldn't be active. Skim the held-open and forced-door alarm history — a door that alarms constantly needs tuning, and one that never alarms may have a dead sensor.
- Twice a year: Check the clock and time zone around the DST changes, and confirm next year's holiday calendar is loaded.
- Annually: Have the system professionally serviced — backup batteries tested and replaced on age, power supplies checked, position switches verified, lock hardware inspected, firmware and licensing brought current.
None of the self-serve items needs a technician. The annual visit does, and it's a fraction of the cost of the emergency call it replaces. Our care plans fold this rhythm into a scheduled routine, including on systems we didn't install.