Quick answer
A composite door that won't close is usually one of three things: the multi-point lock hooks are stuck extended, the door has dropped enough to catch the frame heavily, or the weatherseal has swollen and is physically blocking the door. Never force it — forcing typically bends a hook or cracks the frame, turning a simple fix into an expensive one.
Overview
A door that won't close is usually catching the frame significantly, or the multi-point mechanism is stuck in the engaged position. Either way, don't force it - you'll damage the slab.
Symptoms
- Door stops before it reaches the frame.
- You have to lift the handle before it will close.
- Loud bang when it does close.
Common causes
- Hooks stuck in the extended position.
- Dropped door catching the frame.
- Swollen weather seal.
- Something wedged in the frame or threshold.
Stop before you push harder
The instinctive reaction to a door that won't close is to lean into it, and this is exactly the wrong move on a composite door. The multi-point locking hardware inside the door edge is precision steel, and forcing a door shut against a hook that's caught on a keep plate will bend that hook permanently, requiring a full gearbox replacement rather than a simple adjustment.
The correct first step is always to look, not push: check whether the hooks and bolts along the door edge are extended (meaning the handle is up and the lock is engaged) or retracted. A door with hooks extended cannot close — it needs the handle lifted back down before it will go anywhere near the frame.
The three most common causes, in order of likelihood
By far the most common cause we find on site is simply that the multi-point hooks are extended when the door is being closed — often because the handle was lifted the last time the door was open and never lowered again. The second most common is a door that has dropped enough on its hinges that it's now catching heavily rather than just scraping, effectively wedging it before it reaches the frame.
The third is a weatherseal that's swollen from moisture or heat to the point where it's physically too thick to compress into the gap, particularly on older EPDM seals nearing the end of their working life, which are common on doors installed 10 years ago or more around Cornwall's damper coastal areas.
- Hooks extended: handle needs lowering before the door will close at all.
- Heavy catching: door has dropped significantly, needs a hinge adjustment.
- Physical resistance from the seal itself: seal has swollen or perished and needs replacing.
What a locked-open door means for security in the meantime
If your composite door won't close and you're waiting for a repair, this is a genuine security gap, not just an inconvenience. An external door that can't be fully shut and locked leaves a property vulnerable, and it's a particular concern for holiday lets in Cornwall where a property might sit empty between changeovers.
In the short term, don't leave the property unoccupied with the door in this state. A same-day or emergency call-out is worth the extra cost when the alternative is an insecure home, and most repairs of this type — once correctly diagnosed — take under an hour on site.
Diagnosing a stuck gearbox versus a mechanical obstruction
If the hooks are visibly extended and won't retract even with the handle worked gently up and down, that points to an internal gearbox fault rather than something you can free yourself. Gearboxes fail in a few characteristic ways — a broken return spring, a worn cam, or corrosion inside a mechanism that's been in a damp doorway for years — and a failed gearbox needs replacing rather than freeing.
If the hooks retract fine but the door still won't close, the obstruction is external: check the threshold and frame rebate for debris, a dropped fixing, or in coastal properties, sand and salt-crust build-up that's thick enough to physically block the door's path.
Why this is more common after storms in Cornwall
We see a noticeable spike in 'door won't close' call-outs across Cornwall in the days following autumn and winter storms. Wind-driven rain forces water and debris into door thresholds, sand blows into frame rebates on coastal properties, and sudden gusts that catch a door mid-swing can jolt hinges or bend hardware in a single event rather than through gradual wear.
If your door developed the problem suddenly, right after a windy spell, mention that when booking — it points toward physical obstruction or impact damage rather than gradual mechanical wear, which changes what we bring to the first visit.
A recent case: a granite cottage near Zennor
A cottage near Zennor, fully exposed to Atlantic gusts, had a composite door that stopped closing entirely after a storm. On inspection, wind had caught the door mid-open and forced it back against its own hinges hard enough to distort the top hinge slightly, which in turn caused the top hook to misalign with its keep. The fix was hinge replacement rather than adjustment, since the leaf itself was bent — a reminder that sudden, storm-related failures often need parts rather than a tweak.
What we check first on a callout for a door that won't close
On arrival we never touch the handle first — we look. A visual check of the door edge tells us within seconds whether the multi-point hooks are extended, whether there's visible debris in the frame rebate, or whether the door is sitting noticeably proud of the frame on one side, which points to a drop rather than a lock fault. Only once that's established do we work the handle gently to see whether the mechanism responds normally.
We also check the keeps on the frame side for damage, since a door forced shut against extended hooks even once can leave a keep plate bent or cracked, and a bent keep will stop a perfectly good door closing even after the lock issue itself is resolved. This is why a homeowner's instinct to give it one more firm push before calling us can sometimes turn a five-minute fix into a keep replacement.
When adjustment alone won't get the door closing again
If the cause is a genuinely failed gearbox — a broken spring or a stripped internal cam — no amount of hinge or keep adjustment will help, because the fault sits inside the sealed lock case itself. In that scenario we replace the gearbox, matching the backset and spindle height to the original so the existing handles and cylinder still fit, which keeps the cost down compared with replacing the whole lock case.
Similarly, if wind-driven rain has forced moisture inside an older gearbox and caused internal corrosion, temporary freeing of the mechanism might get you through a weekend, but it isn't a lasting fix — corroded components tend to seize again within weeks, and we'd always recommend replacement over a stopgap once corrosion is confirmed.
CERTASS guarantee position on lock and gearbox failures
Gearbox and multi-point lock hardware typically carry a shorter guarantee than the door slab itself, commonly 1 to 3 years from the original installer, and this cover is usually void if the mechanism has been forced. Because forcing a stuck lock is such a common cause of failure, it's worth having any door that won't close inspected before it's forced again, particularly if the door is still within its original warranty period, so any claim isn't jeopardised by additional damage.
As a CERTASS registered business we record the make and model of gearbox fitted on every job, which makes any future warranty claim on our own repair work straightforward, and gives you a reference if the same fault recurs and needs escalating to the hardware manufacturer directly.
Holiday-let security exposure while a door won't close
For a holiday let, a door that won't close is more than an inconvenience — it's a period where the property may be sitting with no functioning external lock between guest changeovers, which has obvious implications for both security and any let-property insurance conditions that specify locking standards. We treat these as priority call-outs where possible, since an empty coastal property with an insecure door is a genuine risk, particularly outside peak season when a fault might not be noticed for days.
If you manage a let remotely, it's worth having a local point of contact who can grant access quickly, since the fastest part of resolving a won't-close fault is very often simply getting into the property to look at it.
The point where a stuck door becomes an early-warning sign
A single won't-close incident, resolved by lowering a raised handle, is not something to worry about. But a door that repeatedly needs 'jiggling' to close, even when the handle is used correctly, is telling you the mechanism or alignment is drifting, and it will eventually fail to close altogether, usually at an inconvenient moment. Treating the second or third occurrence as worth a call, rather than waiting for a full lockout, is the difference between a £75-£120 adjustment and an emergency out-of-hours visit.
Typical repair costs in Cornwall
| Work | Typical price | Notes |
|---|---|---|
| Diagnosis and handle/hook freeing | £75–£100 | Where the issue is a stuck or misaligned hook |
| Hinge adjustment for heavy catching | £90–£150 | Door has dropped and needs realigning |
| Gearbox replacement | £180–£320 | Where hooks won't retract internally |
| Debris clearance and threshold check | £75–£95 | Usually bundled into the call-out fee |
Guide prices only — we confirm the cost after seeing the door.
When to call a professional
- Hooks won't retract.
- You can't identify what's stopping it.
Prevention
- Never lock a door that isn't fully closed - bends the hooks.
