Door Mechanism Repair · Sale & Greater Manchester
uPVC, composite and bifold door mechanism repair across Sale, Greater Manchester and Cheshire. Gearbox replacement, MPL strip repair, spindle faults and door realignment — we diagnose the correct fault before touching anything.
Fault identification
Most door mechanism problems fall into one of six categories. Identifying the correct fault prevents unnecessary parts replacement and saves time on the day.
Gearbox failure
You can lift the handle fully and the key turns normally, but the hooks and rollers don't extend into the frame. The door won't lock regardless of what you try.
The gearbox — the central drive unit — has failed. This is the most common mechanism fault. The cylinder is not the problem.
Spindle fault
The handle rotates 360 degrees in one or both directions with no engagement. Lifting achieves nothing. The door may have snapped internally while the handle was forced.
The spindle — the connecting bar between handle and gearbox — has snapped. Requires mechanism replacement.
Mechanism seized
The door is jammed shut. The handle won't move, or moves but the door stays locked. You cannot get in or out. This can happen when a partial mechanism failure progresses to a complete seizure.
Non-destructive entry followed by mechanism replacement. Do not force the handle — this can cause additional damage.
Misalignment / hinge wear
The door scrapes, catches at the top or bottom of the frame, requires force to push shut, or has a visible gap at one side when closed. The handle feels stiff to lift even before anything locks.
The door has dropped — usually from hinge wear. This puts the locking points out of line with the keeps in the frame, straining the mechanism. Realignment (toe & heel) or hinge work resolves this.
Partial failure
The door appears to lock — you can hear some clicks — but certain locking points don't engage. The top might lock but not the bottom, or the hooks catch but the deadbolt doesn't extend.
Usually a worn or damaged keep/strike plate on the frame side, or partial gearbox failure. Often progresses to complete failure if left.
Alignment / seal
The door closes and locks, but there is a noticeable draught around the frame, or a gap is visible at the top, bottom, or one side. Cold, damp, or noise is getting through.
Could be hinge misalignment, a worn keep, or the door has twisted slightly. We assess the full door in situ — not just the lock.
If you can hear the mechanism click when you lift the handle, but the bolts don't extend — that is almost certainly a gearbox fault, not a lock fault. Replacing the cylinder won't fix it. We confirm the correct diagnosis over the phone before attending, so you don't pay for the wrong repair.
Door types
Each door type uses a different mechanism and fails differently. Understanding which type you have determines the repair approach and the parts needed.
Front, back and side doors — most common door type in Greater Manchester
uPVC doors use a multipoint locking mechanism — a metal strip running the full height of the door on the closing edge. When you lift the handle, a central gearbox drives hooks, rollers, and deadbolts into receivers in the door frame simultaneously.
When the gearbox fails, the handle movement is disconnected from the locking points. The door can close but not lock. This is a mechanical fault, not a lock or cylinder fault, and requires gearbox or mechanism replacement.
Common failure signs: handle lifts but nothing locks, handle suddenly much harder to lift, or a snap sound followed by complete loss of function.
Front doors — growing across Greater Manchester housing stock
Composite doors use the same multipoint locking principle as uPVC, but with a heavier door and tighter tolerances. Common mechanism makes include Winkhaus, Avocet, and ERA. The heavier door weight means hinge wear and misalignment are more common than on uPVC, and can cause mechanism problems even when the gearbox is fine.
A composite door that won't lock, has dropped at one side, or lets in a draught often requires both a mechanism assessment and a hinge or alignment check — we do both on the same visit.
We do not replace the composite door panel or glazing. We repair and replace the mechanism, handles, hinges, and keeps.
Garden and rear access doors — mechanism faults often mistaken for lock problems
Bifold doors rely on roller carriages running on a top track, bottom pivots, and an alignment rail. When rollers wear, pivots fail, or the track bends, the door drags, comes off the rail, or won't fold flat. These are mechanical faults, not lock faults.
Patio sliding doors use a different mechanism — rollers in a bottom track that bear the full weight of the door. Worn or collapsed rollers cause the door to become heavy, drag, or jam in the track. Lock points at top and bottom can also fail separately from the main sliding mechanism.
Both door types are often misdiagnosed. We assess the full mechanism before recommending any repair.
How it works
Understanding which component has failed determines the repair. Here is what each part does and how it typically fails.
The full metal strip that runs top to bottom inside the door on the closing edge. It holds the gearbox, hooks, rollers, and deadbolts as a single assembly. When the MPL is replaced, the whole locking system is renewed.
The central drive unit that translates handle movement into bolt movement. The gearbox sits in the middle of the MPL strip. When it fails — from wear, force, or misalignment stress — the handle moves but nothing locks.
The metal bar that passes through the door and connects both handles to the gearbox. When the spindle snaps, the handle rotates freely with no effect. Spindle failure is often triggered by forcing a jammed handle or from a worn gearbox that has allowed play to develop.
The frame-side plate with shaped recesses that the hooks and rollers engage into when the door locks. If the keep is in the wrong position (from a dropped door) or worn, the locking points miss the recesses — the door won't fully lock even when the gearbox is working.
Connects the door to the frame and bears the full weight of the door leaf. Worn or damaged hinges allow the door to drop or twist over time. This misalignment puts excess stress on the mechanism and shifts the locking points out of line with the keeps — causing mechanism faults indirectly.
Repair vs replace
Double-glazing companies will often quote for a new door when only the mechanism has failed. Here is what actually needs replacing — and what the difference costs.
In most cases, only the internal mechanism has failed — not the door. Replacing it costs a fraction of a new door and gives you a door that works like new. We tell you honestly which applies — before any work starts.
Transparent pricing
All prices include labour and the replacement part. Exact cost agreed before work starts — no surprises on the day.
Common questions
Answers based on the faults and enquiries we actually see across Sale and Greater Manchester.
A multipoint locking mechanism (MPL) is a metal strip that runs the full height of a uPVC or composite door on the closing edge. When you lift the handle, it drives a central gearbox that simultaneously extends hooks, rollers, and deadbolts into receivers in the door frame. When one part of this system fails — usually the gearbox — the whole locking process breaks down, even though the key and cylinder may be working perfectly.
If the handle moves freely but the bolts don't extend, the gearbox has almost certainly failed. The gearbox is the drive unit between the handle and the locking hooks. It can fail from normal wear, from a sudden snap when the door is forced, or from door misalignment putting excess stress on the mechanism over time. Crucially, a cylinder or key replacement will not fix this — the gearbox is the fault. We confirm this over the phone before attending.
Yes — in almost every case. The mechanism (gearbox, full MPL strip, spindle, or handles) is a separate, replaceable component inside the door. We remove the old mechanism, fit a matching replacement, test the door fully, and leave. The door panel, glazing, and frame stay exactly as they are. A new door is only needed when the frame or panel itself is structurally damaged — which is genuinely rare. Double-glazing companies will often recommend a new door because it's a bigger sale for them. We won't.
Gearbox replacement starts from £95, which includes labour and the replacement gearbox part. A full MPL strip replacement (the complete locking rail) starts from £130. Realignment work — toe and heel adjustment when the door has dropped — starts from £75. The exact price is always confirmed before any work begins. There is no call-out fee, and no charge if the repair doesn't go ahead.
We carry and fit parts from the major mechanism manufacturers including Fuhr, ERA, GU, Maco, Roto, Winkhaus, Yale, Lockmaster, Avocet, Mila, Fullex, and Safeware. Most mechanisms can be replaced same day from van stock. For less common or older discontinued mechanisms, we confirm parts availability before attending — so you are never left with a part-completed repair.
A door that cannot fully lock is a security risk even if it can be physically closed. Most mechanism faults deteriorate progressively — a partial failure becomes a complete failure over weeks or months, and a door that closes but won't deadlock leaves a property unsecured. We recommend not leaving a known mechanism fault unrepaired, particularly on front or back entrance doors. A door jammed in the locked position becomes an emergency; dealing with it while it's still operational is always easier and cheaper.
Same-day assessment where available. Price agreed before we start — no call-out fee.
Every day 08:30–18:30 · Sale, Greater Manchester & Cheshire · Vitaly, VS LOCKSMITH LTD
