GU Door Hardware Repair — London

Specialist repair of GU (Gretsch-Unitas) door hardware across London. Multipoint locks, espagnolette systems, handles and locking mechanisms repaired by specialist engineers.

Book a Survey — £70 Emergency Call-Out

GU Specialists

Expert GU Hardware Repair in London

GU — Gretsch-Unitas — is one of Germany's oldest and most established door and window hardware manufacturers. Unlike system manufacturers who make the entire door profile, GU manufactures the hardware that lives inside the door: multipoint locking systems, espagnolette bars, handles, hinges and associated fittings.

GU hardware is found inside doors made by many of the world's leading manufacturers — including Schüco, Reynaers, Rehau and others. If your sliding or bifold door has a locking or handle fault, there is a strong possibility the underlying hardware is GU-manufactured.

Our engineers have extensive experience diagnosing and repairing GU locking systems. We carry replacement GU components including multipoint lock cases, gearboxes, locking keeps and espagnolette bars for the most common configurations.

Common GU Hardware Faults We Repair

Multipoint lock failure — door won't lock or unlock
Espagnolette bar corrosion or mechanical failure
Locking point disengagement or damage
Gearbox wear — stiff handle or failed gear mechanism
Handle escutcheon failure or damage
Keep plate misalignment preventing full locking
Cylinder replacement on GU lock cases
Security upgrades on older GU locking systems
Shoot bolt failure on bifold door systems
Emergency lockout repair — door locked shut with failed hardware

GU Hardware Systems

GU Hardware We Work With

MLS

GU Multipoint Locking Systems

The most common GU hardware fault we repair. Multipoint systems distribute locking across the full height of the door — when they fail, the door typically cannot be locked or is very difficult to operate.

ESP

GU Espagnolette Systems

Espagnolette bars run the full height of the door and engage multiple locking points simultaneously. Corrosion, mechanical wear and impact damage are the most common failure modes.

HNG

GU Hinges & Stays

GU produces a wide range of concealed and surface hinges for doors and windows. Hinge wear leads to panel drop, draught issues and, in severe cases, difficulty closing the door correctly.

The Process

How We Work

Book a Survey

Hardware Identified

Our engineer identifies the GU component, confirms the fault and quotes for the repair or replacement.

Parts Sourced

We carry a range of GU hardware and can source additional components from our specialist hardware suppliers.

Repaired & Tested

Hardware repaired or replaced and door tested across all operating positions.

Common Questions

GU Hardware Repair FAQs

My door handle is very stiff — is this a GU gearbox fault?

Stiff handle operation is very often caused by gearbox wear inside the door. The gearbox translates handle movement into the locking mechanism — when it wears, operation becomes difficult and eventually fails entirely. Gearbox replacement usually resolves the issue completely.

My door locks at the top and bottom but not in the middle — what's wrong?

This is a classic multipoint locking fault — typically a worn or damaged locking point or keep plate. In most cases only the affected locking point needs replacing, not the entire system.

How do I know if my door has GU hardware?

GU hardware is often branded on the handle escutcheon or visible on the lock case edge of the door. Our engineer can identify the hardware during the survey visit — in many cases GU hardware is identifiable from the style of the locking system.

How much does GU hardware repair cost?

Our £70 survey fee covers assessment and quotation. GU hardware repairs typically range from £150–£700 depending on the component and complexity. All costs are agreed before work begins.