UPVC Door Gearbox Repair: What’s Wrong, and What It Costs to Fix

If your UPVC door handle has gone floppy, won’t lift, or lifts but won’t lock the door, the part that’s failed is almost always the gearbox — the mechanism down the edge of the door that drives the hooks and bolts. Replacing it is usually **£xx to £xx fitted**, with no call-out fee, and we carry the common brands in the van so most jobs are done in one visit.

But before you pay for a new mechanism, it’s worth thirty seconds making sure that’s actually what you need — because a fair number of “I need a new gearbox” calls turn out to be a cheaper fix. This page shows you how to tell, what it should cost, and how to avoid being sold the expensive part when a cheaper one would do.

Locked out or door won’t secure right now? Call 07377 723 711 — you’ll speak to Tee, the locksmith who’s coming.

CALL: 📞 07377 723 711

What a UPVC door gearbox actually is

A UPVC door doesn’t lock like a wooden one. When you lift the handle, you’re driving a multi-point mechanism — a long metal strip down the edge of the door with hooks, rollers and a deadbolt that all shoot out at once and pull the door tight into the frame. The part in the middle that does the driving, the bit that converts your handle-lift into all that movement, is the gearbox.

It’s the single most-worked component in the door. Every lock, every day, for years. So when something on a UPVC door fails, the gearbox is the usual culprit — and it’s also the part people most often get overcharged for.

upvc door closeup of handle area looking at upvc door gearbox mechanism

Is it really the gearbox? A 30-second check

With the door open, lift the handle and watch the hooks and bolts along the edge:

Handle feels floppy, loose or sloppy, and the hooks don’t throw → that’s the gearbox. It’s worn or stripped inside. A new one is the fix.
Handle lifts firmly and the hooks throw fine, but the key won’t turn → that’s the cylinder (barrel), not the gearbox. Much cheaper. See UPVC door lock repair →
Handle and hooks both work, but the door is stiff to lock or you have to lift-and-shove → that’s usually alignment — the door has dropped and the hooks are catching the keeps. Often no new parts at all. See UPVC door alignment →
The handle itself is broken, wobbly at the fixing, or snapped → that may be just the handle, with the mechanism behind it fine. See UPVC handle replacement →

If you lift the handle and it won’t lift at all, or it’s gone completely dead, stop forcing it — that can jam the door shut with the hooks half-out, which turns a straightforward job into a much harder one. Call us and we’ll talk you through it.

What a UPVC gearbox replacement costs

Here’s what the job should land at. These include attendance and labour — there’s no separate call-out fee.

Job	Typical cost
Multi-point gearbox replacement (centre case)	£xxx – £xxx
Full multi-point strip replacement (whole mechanism)	£xxx – £xxx
Euro cylinder swap (if it’s the barrel, not the gearbox)	£xx – £xxx
Anti-snap cylinder upgrade (TS007 3-star)	£xxx – £xxx
Door alignment / adjustment (no new parts)	from £xxx

Why it’s a range, not a single number: gearboxes vary by brand — Fullex, GU, Mila, Yale, Lockmaster and others use different case sizes, backsets and centres. The right replacement has to match what’s on your door. We confirm the likely price on the phone once you tell us the symptom, and the exact price on the doorstep before any work begins. The price we give you is the price you pay.

CALL: 📞 07377 723 711

The overselling trap — and how to not fall into it

The most common way people overpay on a UPVC door is being sold a full mechanism replacement when the centre gearbox case alone — or even a free alignment tweak — would have fixed it.

Here’s the honest version:

If one component has failed, usually the centre gearbox, it’s often possible to replace just that part rather than the entire strip. Cheaper, and just as durable.
If the whole mechanism is worn, seized, or an obsolete pattern that can’t be matched, a full replacement is the sensible fix and will outlast a patch.
If the handle lifts firmly and the hooks throw smoothly with the door open, the mechanism is fine — and anyone quoting you for one hasn’t diagnosed it properly.

Before you agree to a “full mechanism replacement,” ask the locksmith to show you exactly what’s failed. We’ll do that as a matter of course: diagnose it on the doorstep, show you the worn part, and only charge you for what actually needs replacing.

What happens when you call

You speak to Tee, the locksmith who’s coming — not a call centre that sells your job on. Tell him the symptom (handle floppy, won’t lock, key won’t turn) and your postcode, and he’ll give you a price band on the phone and an arrival time.

On the doorstep he diagnoses it free before anything is fitted. A gearbox replacement means taking the mechanism out of the edge of the door, matching the replacement to the same backset and centre measurements, refitting and resetting the handles and keeps so it all lines up, then testing the door several times from both sides. The van carries the common cylinders and the popular gearbox brands, so the large majority of jobs are finished the same visit rather than “I’ll have to order the part.” You get an itemised receipt showing the labour and the exact part fitted.

CALL: 📞 07377 723 711

How long does it take?

gearbox replacement is usually 30 minutes to just over an hour, depending on the brand and whether the replacement is a direct match or needs adapting. A straight cylinder swap, if that turns out to be all you need, is quicker — 15 to 20 minutes including testing the new keys.

Can I replace a UPVC gearbox myself?

Honestly, it’s not a good DIY job. Unlike a euro cylinder — which a confident DIYer can sometimes manage if they measure it right — a multi-point gearbox has to be matched on three measurements (backset, centre, and handle pattern), and forcing in a near-match usually makes things worse or leaves the door insecure. The mechanisms also aren’t cheap to buy as a one-off, so a wrong guess is an expensive mistake. If you want to check what you’re dealing with before calling, send us a photo of the mechanism along the door edge and we’ll tell you what it is.

Common questions

How much does a UPVC door gearbox replacement cost?
Typically £xxx to £xxx fitted, including labour and with no call-out fee. The range depends on the brand of mechanism on your door — Fullex, GU, Mila, Yale and others differ in price. We confirm on the phone and give you the exact figure before any work starts.

My handle’s gone floppy — is that the gearbox?
Almost certainly. A floppy or loose handle that won’t throw the hooks is the classic sign of a worn or stripped gearbox. Don’t keep forcing it, as that can jam the door shut.

Can you just replace the gearbox, or do I need the whole mechanism?
Often just the centre gearbox case, which is cheaper than the full strip. We only replace the whole mechanism if it’s genuinely worn out or can’t be matched. We’ll show you which it is before fitting anything.

My door’s gone stiff and I have to lift hard to lock it. Is that the gearbox?
Usually not — that’s more often alignment. The door has dropped slightly and the hooks are catching the keeps. It’s frequently a free adjustment rather than a new part.

Do you carry the parts, or is it two visits?
We carry the common cylinders and popular gearbox brands in the van, so most jobs are done in one visit.

Is there a call-out fee or night surcharge?
No call-out fee, and no night surcharge — the same rate whatever the hour.

Are you qualified?
City & Guilds qualified, DBS checked, and listed on TrustATrader, with a guarantee on all work.