The seven faults that account for nine in ten of our callouts — what each one looks like, what causes it, and the cheapest route back to a working door. Plain-language diagnosis from UK commercial door engineers.
These are the search terms our customers actually type when something has gone wrong. Each fault has its own page with the symptoms, the underlying cause, the repair route and an FAQ block.
Why commercial doors drop, sag and drag on the threshold — worn bottom pivots, top centres, floor springs and frame movement. UK engineer diagnosis and repair routes.
Diagnose → Symptom · Oil on threshold · 6 minWhy commercial floor springs leak, the warning signs (oil on the threshold, slow close, hard slam) and how UK door engineers replace them.
Diagnose → Symptom · Looseness, drag, drift · 6 minBroken commercial door pivots — symptoms, causes and replacement routes for bottom pivots, top centres and bottom shoe systems on aluminium and glass doors.
Diagnose → Symptom · Hookbolt jamming · 6 minSticking APG (all-purpose glass) door locks — why hookbolts jam, what causes lock-cylinder failure, and how UK engineers replace APG locks in retail and commercial doors.
Diagnose → Symptom · Closer above the door · 6 minFailed transom closers on commercial doors — oil leaks, slamming, slow close, stop-short. UK engineer guide to symptoms, diagnosis and transom replacement.
Diagnose → Symptom · Catches on open · 6 minAluminium shopfront and office doors that drag on the threshold — the underlying mechanical causes and the repair routes for retail and commercial entrances across the UK.
Diagnose → Symptom · Door won't open or won't close · 6 minFailed automatic door sensors — PIR activation, microwave activation, safety beam and presence sensor faults on UK commercial automatic doors. Engineer diagnosis and replacement.
Diagnose →Yes — most diagnoses are completed remotely from a photo, a short video and a description. Same-day quotes are the norm; same-day dispatch where the fault is urgent and the parts are in stock.
Yes — we operate UK-wide with engineers across England, Wales and Scotland. Multi-site retail and managed-property customers are supported through a single contract covering all locations.
Our standard response window for a secured building (door not locking, fire route compromised, glazing damage) is 2–4 hours within most of the UK. Same-day for non-emergency repairs in the large majority of cases.
Yes — most retail, hospitality and healthcare customers schedule repairs out of hours. There is no out-of-hours surcharge on planned work booked through a service contract.
Yes — every job has a fixed-price written quote before any engineer is dispatched. Where the fault requires additional work once on site, we issue a revised quote and seek approval before continuing.
A photo, a 10-second video and a sentence about when it started is usually enough for a written quote the same day — no site visit needed in most cases.
Get in touch
Head Office:
Commercial Door Maintenance and Security Ltd
61 Bridge Street,
Kington,
HR5 3DJ
t: 0800 774 7998
e: info@cdms-ltd.co.uk
Office Hours
Mon - Sat: 8am - 10pm
Sun: Closed
