GU (Gretsch-Unitas) Hardware Repair

Gretsch-Unitas (GU) develops technology for windows, doors and buildings. UNI-JET is a major family in its current window-hardware range and is used in PVC, timber and aluminium constructions. FERCO is a Gretsch-Unitas Group company and also manufactures window hardware.

We service standard GU / FERCO window hardware within our window-mechanism service scope. We keep this separate from GU door technology: SECURY is an official family of multipoint door locks and is not a standard window-hardware system. HST / lift-and-slide systems and entrance or exterior doors that require locksmith work or security-system service are outside our normal scope.

UNI-JET and FERCO – why does exact identification matter?

GU describes UNI-JET as a modular hardware system for a wide range of windows and French doors. Current manufacturer literature distinguishes solutions by profile material and hinge-side construction. The UNI-JET range includes configurations for PVC, timber and aluminium, with different visible or concealed hinge-side designs.

That distinction matters during repair. A GU or FERCO marking does not identify a replacement component by itself. An older window may contain an earlier generation, a different hinge-side variant or a component with different dimensions. Before selecting a part, we therefore check markings, construction, profile material and how the component interfaces with the rest of the mechanism.

How can you help identify GU / FERCO hardware before the visit?

• Look for markings on the faceplate, corner component, hinge, stay or another visible hardware element.
• Photograph the complete sash so that the window type and hinge side can be seen.
• Take a close-up of the faulty area and a readable photograph of any numbers or symbols.
• Do not dismantle the mechanism simply to find a marking. If the designation cannot be seen safely, we can identify it during on-site diagnostics.

Photographs can often narrow down the product family before the visit, but they do not replace measurements and inspection of the installed mechanism.

Which symptoms justify GU / FERCO hardware diagnostics?

• the sash rubs against the frame or has visibly shifted;
• the handle has become noticeably stiffer or no longer moves correctly between positions;
• the window does not close, tilt or lock correctly;
• a hardware component has play, cracking, deformation or unusual wear marks;
• the closed sash no longer contacts the frame evenly.

None of these symptoms identifies a single failed part on its own. Similar behaviour can result from sash geometry, hardware adjustment, component wear, fastening problems or several causes at once. We therefore do not order a replacement component solely from a description such as “my GU window will not close”.

How do we service GU / FERCO window hardware?

1. Identify the system and construction

We check markings, profile material, component layout, hinge-side arrangement and the functions of the specific window. The brand is a starting point, not a complete part number.

2. Assess sash geometry and hardware operation

We inspect sash movement, hinges, locking components, the handle drive and the corresponding keeps that are present in the installed construction. The aim is to establish why the window is resisting or sitting incorrectly rather than masking the symptom with an arbitrary adjustment.

3. Adjust where the system allows

If the construction and component condition permit adjustment, we correct sash position and the cooperating hardware in accordance with the installed system. We do not advertise a universal number of “adjustment points” because hardware and window configurations differ.

4. Repair or replace the failed component

Replacement selection follows identification of the system, dimensions and interaction with the remaining hardware. Depending on the generation and current availability, the solution may use a manufacturer component or a compatible service part. We do not promise that every historical component is immediately available before identification.

5. Verify operation after service

We test the functions provided by the specific window, including opening, tilting, closing, handle operation and locking. If the original complaint also involves gaskets, sash geometry or another independent issue, we explain that separately rather than presenting every problem as a hardware failure.

Maintaining GU / FERCO window hardware

Maintenance requirements depend on the exact system and the relevant manufacturer documentation. Moving and interacting components should be checked for wear, secure fastening and correct operation. We do not apply one lubricant or one maintenance interval to every GU / FERCO generation without first checking the appropriate instructions.

What can you check safely yourself?

You can record visible markings, note when the problem occurs and check whether the sash is rubbing against the frame. Do not force a stiff handle and do not turn unidentified adjustment screws at random. A paper test can indicate a difference in resistance at one point, but it cannot determine whether the cause is hardware adjustment, sash geometry, a gasket or another component.

Brands we work with

Regardless of the hardware manufacturer, we most often service wear-and-tear components that naturally degrade over time.

• VEKA, Salamander, Aluplast, Rehau – European PVC systems, among the most commonly found in Polish residential construction.
• Drutex, Oknoplast, MS Więcbork – Polish manufacturers found in newer residential developments.
• Schüco, Aluprof – aluminium windows and HST patio doors used in modern construction.
• Roto, Winkhaus, Maco, Siegenia – manufacturers of hardware and multi-point locking systems.
• Velux, Fakro – roof windows commonly installed in detached houses.

We use original spare parts or high-quality replacements — depending on the manufacturer and component availability.

How does our service work?

The service process is simple and transparent — six steps from first contact to warranty:

• Contact – fill in a short form or call us. We call back within approximately 15 minutes.
• Free on-site diagnostics – a technician arrives at the agreed time and assesses the condition on site.
• We explain the cause – we show you exactly what needs to be repaired.
• We present the cost – after diagnostics we provide an exact quote. No hidden fees.
• We carry out the repair – after your approval we complete the work, most often during the same visit.
• You verify the result – we test the outcome together. You receive a service report, a warranty on the work performed, and the manufacturer's warranty on original parts.

Where do we provide GU hardware service?

We provide GU / FERCO window-hardware service in Warsaw, Krakow and Katowice, as well as other locations within our active service regions. See the current list of cities we serve →

How much does GU / FERCO window-hardware service cost?

Our current price list shows starting prices of 50 PLN for window adjustment and for mechanism replacement. The final cost of GU / FERCO service depends on the diagnosed fault, exact system, required parts and actual scope of work. On-site diagnostics and technician call-out are free, and we provide the exact quote before paid work begins.

An indicative service price list is available separately. After registration, we contact you within about 15 minutes to collect information about the problem and agree the next step.