7) Schedules and bank-holiday rules misbehave
What you’ll see. Doors stay open late, cleaners can’t get in on a holiday, or time-zones seem “off”.
Likely causes. Controller clock drift, wrong time-zone/DST setting, or a missing entry in the holiday table. In cloud-managed platforms, the site may be pinned to the wrong region; in multi-site estates, only some sites received the new calendar.
How to fix. Point controllers and servers at a reliable NTP source, check the estate’s time-zone/DST rules, and use a single, re-usable holiday list across sites. Audit schedules quarterly and before public holidays.
Prevent it. Add time-sync and schedule reviews to your BAU runbook; make a change request whenever HR updates holiday policy.
8) Controller or door goes “offline” on the network
What you’ll see. A door reports offline in the admin console; events buffer and flood in later, or the door appears to stop enforcing policy.
Likely causes. VLAN/firewall changes, DHCP lease problems, Spanning Tree/timeouts on edge ports, or PoE brown-outs during switch failover. In cloud models, a proxy or SSL inspection can also upset controller communications.
How to fix. Confirm the controller’s addressing and switchport state, disable unnecessary “helpful” features (e.g., security devices often prefer fixed portfast-like configs), and ensure the management plane is reachable through the firewall policy intended for the platform. Architecturally, design for deterministic decisions at the edge so doors keep enforcing cached permissions during WAN/server hiccups, then reconcile later—this is consistent with recognised EACS performance baselines.
Prevent it. Place devices on a segmented VLAN, document firewall rules, and monitor link flaps so you catch patterns before they bite. If you’re modernising the wider estate, our overview of IP Security System Installation shows how to build a resilient fabric for converged security.
9) Wireless locks misbehave (lag, missed updates, flat batteries)
What you’ll see. Credentials take too long to propagate; some doors don’t pick up policy changes; battery warnings arrive late—or not at all.
Likely causes. Gateways are poorly sited or under-provisioned; battery change cycles aren’t aligned to duty cycles; firmware update windows are ad-hoc.
How to fix. Survey radio coverage properly, add gateways where needed, and schedule synchronisation more frequently during onboarding bursts. Implement a battery replacement cadence and log it like any other critical component. Fold wireless devices into your formal maintenance plan; NSI’s code of practice sets expectations for documenting power arrangements, maintenance responsibilities and software support—use it to structure supplier commitments.
Prevent it. Treat batteries and firmware as first-class assets in your PPM; alert on low-battery and sync failures to a monitored queue, not a shared mailbox.
10) Electrical gremlins: nuisance resets, random lock releases
What you’ll see. Devices reboot spontaneously; a lock releases when a nearby motor starts; faults vanish when the electrician leaves.
Likely causes. Under-rated or poorly earthed power supplies, noisy mains, shared circuits with inductive loads, or ad-hoc extensions that don’t meet wiring best practice.
How to fix. Isolate supplies, fit appropriately rated PSUs with clean standby, separate security devices from “dirty” loads, and ensure earthing/bonding meets standard practice. When in doubt, bring works back to the recognised UK electrical baseline—BS 7671—which the HSE treats as the benchmark for electrical safety in installations.
Prevent it. Document circuits and label terminations; supervise PSUs; and include controlled power-loss tests in commissioning so you know behaviour under fault.
When fixes should come with paperwork
Quick wins are fine, but access control protects people and assets; fixes should be engineered and evidenced. If you’re replacing hardware, altering fire interfaces, or materially changing behaviour, align the outcome to BS EN 60839-11-1 (system & component requirements) and deliver the work to a recognised code such as NSI NCP 109 so acceptance, documentation and testing are predictable. That approach keeps your insurer and auditors happy—and it prevents the same fault returning under a different name.
Need a hand?
If you want a structured health-check that finds and fixes these issues in one pass—and leaves you with clean documentation and trained admins—our engineers can help design, remediate and future-proof your estate. (See: Commercial Access Control Installation)
