Last updated: March 2026

Window and door mechanism specialists

uPVC Mechanism Replacement in Manchester

The mechanism inside your uPVC window or door is what makes it lock, seal, and stay secure. When that mechanism fails, the window will not close properly, the door will not lock, and your property is left vulnerable. We specialise in replacing uPVC mechanisms across Greater Manchester, carrying a massive range of parts so we can match your existing system and get it working again on the same day.

uPVC mechanisms come in dozens of different configurations. Espagnolette gearboxes for windows, multi-point lock mechanisms for doors, cockspur handles for older casement windows, tilt-and-turn gearboxes, and inline espagnolette systems. Each one has specific dimensions that must be matched precisely. We have been doing this for over ten years and have built up a parts library that covers the vast majority of systems installed in properties across Manchester.

Call 07411 496213 Get a Free Quote

uPVC multipoint lock mechanism being replaced in Manchester

Door mechanism gearbox stripped for replacement

How uPVC Mechanism Replacement Works

Every uPVC mechanism replacement starts with accurate identification. We need to match the brand, the backset measurement, the centres between fixings, the overall length, and the type of locking points. Getting any of these wrong means the replacement will not fit. We take all measurements on site using precision tools, and in most cases we can identify the mechanism from markings on the faceplate or gearbox without needing to remove the entire strip.

For windows, the process involves removing the sash from the frame, stripping out the old mechanism from the groove in the sash edge, fitting the new mechanism, and re-hanging the sash. We then test every locking point to confirm they engage cleanly with the frame keeps. If any keeps have shifted or worn, we adjust or replace those too. The window should close, lock and seal just like it did when it was new.

For doors, we remove the handle, unscrew the faceplate, and slide the old mechanism out through the top or bottom of the door edge. The new mechanism slides in, we reconnect the handle and cylinder, and test the entire locking sequence. We check that the hooks, rollers, and shootbolts all extend fully and engage with the keeps, and that the key and handle operation is smooth.

The whole process takes between thirty minutes and ninety minutes per window or door, depending on accessibility and the complexity of the mechanism. We tidy up completely, dispose of the old parts, and walk you through how the repaired window or door should be operated. Every replacement comes with our standard 12-month guarantee on parts and labour.

Signs Your Mechanism Needs Replacing

These symptoms all point to a mechanism that is failing or has already failed.

Handle turns but nothing locks

When the espagnolette gearbox inside your window or door strips, turning the handle no longer drives the locking cams or hooks into the frame. The handle spins freely or moves without any resistance. This is the most common mechanism failure and it means your window or door is completely unsecured. We replace the gearbox and restore full locking function.

Window or door will not close flush

If the locking cams are not pulling the sash or door tight against the frame seal, you get draughts, rain ingress, and poor sound insulation. This can be caused by worn cams that have lost their profile, misaligned keeps, or a gearbox that is not delivering full travel to the locking points. We replace the worn components and adjust the keeps so the seal is tight all the way round.

Mechanism stuck in the locked position

A jammed mechanism can lock a window shut permanently, which is both a security concern and a fire safety issue. We use specialist tools to release the locked cams from the frame keeps without damaging the uPVC profile, then replace the failed mechanism. If you have a first-floor window stuck shut, we can work from inside the property in most cases.

Cockspur handle snapped or worn

Cockspur handles are found on older uPVC casement windows. They lock by hooking over a peg on the frame when the handle is turned. The nose of the handle wears down over time, or the handle snaps at the pivot. We fit replacement cockspur handles and check that the frame peg is in good condition. If the peg is worn too, we replace it for a secure lock.

Why Choose Us for Mechanism Replacement

uPVC mechanisms are all we do. Here is why that matters.

Massive Parts Range

We carry mechanisms from dozens of manufacturers in our van. Same-day replacement for most systems.

Precise Identification

We measure and match every dimension on site. No guesswork, no ordering the wrong part.

No Call-Out Fee

We quote on site for free. If you decide not to go ahead, there is nothing to pay.

Windows and Doors

We replace mechanisms in uPVC windows, doors, French doors and tilt-and-turn systems.

Full Testing

Every locking point is tested before we leave. We do not sign off until the seal is perfect.

12-Month Guarantee

Parts and labour covered for a full year. Peace of mind with every mechanism we fit.

Mechanism Replacement Pricing

Labour from £69. No call-out fee. A window mechanism replacement including parts is typically £79 to £120. Door mechanism replacements run from £120 to £200 depending on the brand and locking configuration. Multi-window discounts are available.

Mechanism Needs Replacing?

Call us now. We carry hundreds of different mechanisms and can usually replace yours the same day. No call-out fee.

Call 07411 496213