uPVC Door & Window Lock Experts
Specialist repair and replacement of multipoint locking systems, gearboxes, and Euro cylinders for all uPVC doors and windows across East and North London.
Why uPVC Locks Fail
uPVC doors and windows use complex multipoint locking systems that engage multiple hooks, bolts, and rollers simultaneously. When any component wears out — and they do — the whole mechanism can fail, often without warning.
Unlike a simple deadbolt, a uPVC gearbox contains dozens of moving parts under constant spring tension. Daily use, exposure to the elements, and even temperature changes all accelerate wear. Most failures happen gradually, but some happen suddenly, leaving you locked in or out.
We carry the most common replacement gearboxes and cylinders on our van, which means most uPVC lock jobs are completed in a single visit — usually within 30–45 minutes.
Gearbox Failure
The most common failure — the internal gearbox mechanism wears out, making the lock stiff, impossible to operate, or completely seized. Usually repairable with a direct replacement.
Worn Cylinder
Cylinders wear over years of use or can be damaged in attempted break-ins. A worn cylinder is also a serious security risk — upgrading to an anti-snap version is strongly recommended.
Door Misalignment
A sagging or warped door frame causes the lock bolts to miss their keep. This creates strain on the gearbox and often looks like a lock fault — but the real fix is adjustment, not replacement.
Handle Spindle Failure
The spindle connecting the handle to the gearbox can shear or wear through. When the handle drops or spins freely, it usually means the spindle has failed rather than the gearbox itself.
How We Fix It
We follow a methodical diagnosis process to make sure we fix the root cause — not just the symptom. No guesswork, no unnecessary parts.
Initial Assessment
We listen to what the lock is doing — or not doing — and inspect the door, frame, and handle before touching anything. We need to understand the full picture first.
Fault Diagnosis
We identify whether the issue is the gearbox, cylinder, spindle, alignment, or the keep plate. This tells us exactly what needs replacing or adjusting.
Part Matching
We measure the gearbox case size and cylinder dimensions on-site. Most common sizes are on the van. Unusual sizes can be sourced and returned same day or next morning.
Repair & Test
We fit the replacement part, adjust the door and frame if needed, and test the lock through its full range of operation before we consider the job complete.
Every Door Type, Covered
Multipoint locking systems vary by door type and manufacturer. We work on all of them — from simple back doors to complex composite and sliding systems.
uPVC Front Doors
The most common multipoint lock type. We service all standard gearbox sizes including ERA, Yale, Winkhaus, Maco, and Avocet, plus full cylinder replacement and anti-snap upgrades.
French & Double Doors
French doors often have a passive and active leaf with separate locks on each. We align both leaves, service both gearboxes, and adjust the top and bottom espagnolette rods.
Patio & Sliding Doors
Sliding patio doors use a hook-bolt system that is susceptible to roller wear and frame drop. We repair and replace hook bolts, inline gearboxes, and the bottom roller assemblies.
Composite Doors
Composite doors use the same multipoint mechanisms as uPVC but are heavier, making alignment issues more common. We carry the long-case gearboxes specific to composite door profiles.
uPVC Windows
Casement, tilt-and-turn, and top-hung window locks all use different mechanisms. We repair espagnolette locking strips, cockspur handles, window restrictors, and shoot-bolt systems.
uPVC Back Doors
Back doors are often the most neglected — and the most vulnerable. Many older rear uPVC doors still have single-point deadbolts. We upgrade them to full multipoint systems where needed.
When to Call Us
Most uPVC lock failures give warning signs before they fail completely. If you notice any of these, don’t wait — early repair is always cheaper than an emergency callout.
Key Won’t Turn Smoothly
Stiffness or grinding when turning the key is usually a worn cylinder or gearbox under strain. Left untreated, it will seize completely — often at the worst possible time.
Door Won’t Lock or Unlock
If the handle lifts but the lock points don’t engage, or the key turns but the bolts won’t retract, the gearbox mechanism has likely failed or the door has dropped out of alignment.
Handle Has Dropped
A handle that sags downward or no longer operates the lock is a classic sign of spindle failure. The spindle inside the gearbox has sheared — a quick, inexpensive fix if caught early.
Door Is Difficult to Close
If you have to lift the door or push hard to get it to latch, the frame has dropped or the keep plate has shifted. Forcing it puts enormous strain on the gearbox and will accelerate failure.
Security Upgrade Required
Many older uPVC doors still have standard cylinders that are vulnerable to snapping. Upgrading to a TS007 3-star anti-snap cylinder is a quick, affordable security improvement.
Lock Is Making Noise
Clicking, grinding, or rattling sounds when operating the lock or handle indicate worn internal components. The gearbox is telling you it is close to failure — address it before it becomes an emergency.
The Biggs Difference
We have built our reputation on reliability, transparency, and technical expertise. Here is what that means in practice.
No Call-Out Fee
You only pay for the work carried out. There is no charge just for us to come and assess the job — our quote is always free, with no obligation to proceed.
Available 24/7
A uPVC gearbox does not choose convenient hours to fail. We are available every day of the year — including bank holidays and weekends — at the same rates.
DBS Checked & Insured
We are fully DBS checked and carry public liability insurance. You can trust us in and around your home — and so can your insurance company.
All Brands Covered
ERA, Yale, Winkhaus, Maco, Avocet, Millenco, Shootbolt — we carry and work on all major multipoint lock brands. Unusual makes sourced quickly from our local suppliers.
Parts Stocked on Van
We carry the most common gearbox sizes, cylinder lengths, and spindle types on the van. The majority of uPVC jobs are completed in a single visit with no waiting for parts.
5-Star Google Rating
Our reviews speak for themselves. We are proud of our 5-star rating — earned through reliable work, fair pricing, and treating every customer’s home with care and respect.
What Our Customers Say
Real reviews from real customers in East and North London.
My front door gearbox failed completely — I could not lock it at all. Ivor came out within an hour, diagnosed the fault straight away, and had the replacement gearbox on his van. Done in under 40 minutes. Brilliant service, very fair price.
The handle on my back door had been dropping for months. Ivor came and explained exactly what was wrong — the spindle had sheared. He replaced the gearbox and fitted anti-snap cylinders while he was there. Really professional, talked me through everything.
Our French doors had been difficult to lock for a year. Several locksmiths told me I needed new doors. Ivor adjusted the frame and replaced both gearboxes and they work perfectly. Saved us thousands. Wish we had called him first.
East & North London, Covered
Based in Chingford E4, we cover a wide area across East London, North London, and West Essex. If you are unsure whether we cover your area, just give us a call.
Not sure if we cover you? Call us and we will let you know within seconds.
Check Your Area — 07971 565246uPVC Lock FAQs
Answers to the questions we hear most often about uPVC door and window locks.
What is a multipoint locking system?
A multipoint locking system is a mechanism fitted to uPVC, composite, and aluminium doors that engages several locking points simultaneously when you lift the handle and turn the key. Rather than a single deadbolt, the system drives multiple hooks, bolts, and rollers into the door frame at different heights. This makes the door significantly more secure than a single-point lock and is standard on virtually all modern external uPVC doors.
How do I know if my gearbox has failed?
Common signs of gearbox failure include: the handle lifting but the lock points not fully engaging; the key turning but the door not locking or unlocking; a handle that drops or spins freely; grinding or stiffness when operating the handle; or the door locking in one direction but not the other. If any of these apply, call us — the gearbox is the most likely cause, and it is a straightforward repair in most cases.
Can you replace just the cylinder, or do I need a whole new lock?
In most cases we can replace just the cylinder without touching the gearbox, and vice versa. The cylinder and the gearbox are separate components, even though they work together. If the key is stiff or difficult to turn, the cylinder is usually the issue. If the handle is the problem, it is more likely the gearbox or spindle. We always diagnose before recommending any replacement to ensure you only pay for what is actually needed.
How long does a uPVC lock repair take?
Most standard gearbox or cylinder replacements take between 30 and 60 minutes once we are on-site. The diagnosis itself usually takes around 10 minutes. If we have the correct replacement part on the van — which we do in the majority of cases — the entire job including testing is typically done within the hour.
What brands of uPVC locks do you work on?
We work on all major brands including ERA, Yale, Winkhaus, Maco, Avocet, Millenco, Fuhr, Siegenia, and Ferco. We carry the most common gearbox sizes on the van — the standard 28mm, 35mm, and 45mm case sizes cover the majority of doors in our area. For unusual or older mechanisms we have supplier accounts that allow us to source parts quickly, usually within a few hours.
Is it worth upgrading to anti-snap cylinders?
Yes — very much so. Cylinder snapping is one of the most common methods used to break into uPVC doors. A burglar inserts a snap tool, applies force, and the standard cylinder breaks at a weak point, allowing the lock to be operated without a key. Anti-snap cylinders (rated TS007 3-star) are designed so that when force is applied, only the outer section breaks — the part inside the door remains intact and the lock stays secure. The upgrade typically costs around £60–80 all in.
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