Fixed price before we start · No call-out fee · 12-month guarantee
Fixed price before we start · no call-out fee

uPVC & Composite Door Lock Repair

Stiff handle, door won't lock, or the mechanism's given up? Cosmo Locksmith repairs and replaces uPVC multipoint locks and realigns the door so it locks smoothly again.

4.9 on Google · 187 reviews Usually 20–40 min No call-out fee DBS-checked
uPVC & Composite Door Lock Repair
DBS-checked engineers No call-out fee Non-destructive entry British Standard locks Fixed price up front 12-month guarantee

Upgrade the cylinder while we're there

The euro cylinder in most uPVC doors is the weakest point in the house — a standard one can be snapped in seconds. We'll fit a TS007 3-star anti-snap cylinder at the same time if yours isn't one already, which is what insurers now expect and what actually keeps burglars out.

The handle you have to lift with both hands

Almost every uPVC and composite door in the country runs on a multipoint lock: lift the handle, bolts shoot into the frame, turn the key. When it starts sticking, the handle gets stiff or the door won't lock at all, it's usually the gearbox in the mechanism wearing out, or the door dropping on its hinges so the bolts miss the keeps. Both are everyday fixes for Cosmo Locksmith — not a reason to replace the door.

Mechanism repair and replacement

We carry the common multipoint gearboxes and full strips on the van and can match the vast majority of brands, including discontinued ones. If the gearbox has failed with the door locked shut, we open it non-destructively first, then swap the mechanism. Handles, keeps and hinges are replaced where they're worn.

Realignment: the fix most people miss

Half of 'broken' uPVC locks are simply doors that have dropped a few millimetres over the years. We adjust the hinges and keeps so the bolts line up again, and the handle goes from a two-handed heave back to a one-finger lift. We do this on every uPVC job, not just when you ask.

Lockouts
from £59
Lock changes
from £75
Call-out fee
none, ever
  • DBS-checked, fully insured engineers
  • British Standard locks on every van
  • Non-destructive entry wherever possible
  • 12-month guarantee on parts and labour
FAQ

Questions people ask us

My uPVC door won't lock — do I need a new door?+

Very rarely. It's almost always the multipoint mechanism or the door alignment, both of which we fix in one visit.

Can you repair a patio or French door?+

Yes — sliding patio doors, French doors and composite doors all use similar multipoint hardware we carry.

The door is stuck locked shut. Can you still fix it?+

Yes. We open it non-destructively first, then replace the failed mechanism.

Is the repair guaranteed?+

Every mechanism we fit and all our labour is guaranteed for 12 months.

Other services
01

Emergency Lockout Service

Locked out of your house, flat or shop? Cosmo Locksmith opens the door fast and without damage, 24 hours a day — usually within 30 minutes.

From £59
Read more
02

Lock Change & Replacement

New tenancy, lost keys or a worn-out lock — Cosmo Locksmith supplies and fits British Standard locks on the spot, keyed-alike if you want one key for every door.

From £75
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03

Burglary Repair & Boarding Up

Forced door or broken frame after a break-in? Cosmo Locksmith boards up, repairs the damage and fits new locks the same day, with a written report for your insurer.

Read more
04

Moving House Lock Change

You don't know who still has keys to your new place. Cosmo Locksmith changes every external lock in one visit — often the day you complete — all keyed alike.

Read more
05

Commercial & Security Upgrades

Shops, offices, HMOs and landlords: master-key systems, high-security cylinders, smart locks and a free security survey with every visit from Cosmo Locksmith.

Read more
Reviews

What our customers say

4.9 on Google · 187 reviews

“Snapped the key in the lock on a Sunday morning. Out within the hour, key extracted, new cylinder fitted, and the chap even oiled the hinges while he was at it.”

Eleanor W. · Richmond · Snapped key · 5 days ago

“We'd just bought the house and wanted every lock changed. One visit, keyed alike, and a proper explanation of what BS3621 actually means for the insurance. Very reassuring.”

Graham T. · Epsom · Moving house · 2 weeks ago

“Honest to a fault — told me the lock could be repaired rather than replaced and charged accordingly. Rare these days.”

Nadia K. · Sutton · Lock repair · 3 weeks ago
Areas we cover

uPVC locks across 10 towns

We don't do car keys. Cosmo Locksmith is a home and business locksmith. For vehicle lockouts or key programming you'll want an auto locksmith.

uPVC locks, sorted today.

Honest prices · Tidy work · Engineers who turn up

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