Siegenia Aubi bifold door repair.

Siegenia-Aubi is a German hardware manufacturer whose folding gear is fitted into uPVC, timber, and aluminium bifold doorsets from many profile suppliers. The hardware itself is often the useful identification point rather than a badge on the doorset, so Pro-Lock inspects the rollers, hinges, locking gear, and threshold before confirming the fitted generation.

Positioning

Siegenia-Aubi makes folding and sliding hardware rather than complete bifold doorsets. PORTAL FS and related folding gear are fitted into timber, PVC and aluminium profiles, so both the hardware generation and the surrounding profile system matter.

Siegenia-Aubi PORTAL FS running gear, gear generation and profile interfaces — what we see most on Siegenia Aubi doorsets

A Siegenia-Aubi guide may be a bottom bogie or roller assembly, head guide, panel hinge, hook-bolt lock or handle gearbox within another manufacturer's doorset. The same hardware name can appear across different profiles, so we identify the actual generation and track before sourcing parts.

PORTAL FS spare-parts information distinguishes older and newer roller sets, including differences in track fit. A stiff or dropped panel therefore requires the running gear, guide rail, hinge pins and threshold alignment checked together rather than assuming a generic part will solve it.

Siegenia maintenance literature calls for clean running rails and acid-free, resin-free lubrication on the relevant moving and locking parts. We also check loose fixings, bent linkages and the relationship between the gear and its keeps, while recognising that profile distortion may be the real cause.

What the assessment actually involves.

It starts with more than a quick look at the handle. Every assessment follows the same nine-stage assessment process, because that is the only way to quote accurately.

We start with the background and history of the doorset, then take extensive measurements for distortion and check the frame for square and twist. We test operation under load, check drainage paths, and inspect glazing, gaskets and packers. Where parts are involved, components and part numbers are verified against the manufacturer, and every measurement and observation is cross-checked against the manufacturer’s recommended tolerances. Only once that cross-check is complete do we provide an accurate quotation.

The full process is set out stage by stage on our How it works page.

Open the assessment process

What we assess

Fractured or damaged hinges
Broken, worn, or disconnected rollers
Dragging, dropped, or misaligned panels
Panels catching the threshold or header
Difficult closing or locking
Faulty locks, cylinders, handles, keeps, tracks, guides, and seals

Cause, not just symptom

Pro-Lock checks the complete doorset and aims to return it to operation as intended by the manufacturer, rather than treating only the immediate symptom. This helps prevent unnecessary stress transferring to mechanical components, reduces the cycle of repeat repairs, and maximises long-term reliability and service life.

Your assessment is carried out by an experienced engineer, not a salesman. We complete an in-depth assessment of all aspects of your bifold doorset, talk you through the findings while we are on site, and provide the information in the report that accompanies the quotation for any repairs recommended.

The findings are followed by a comprehensive report and itemised quotation by email, with repairs arranged separately. No repair work is carried out during the assessment.

The £79 fee covers a professional bifold-door assessment of the complete doorset. £79 professional assessment, credited against any repair, or refunded if we cannot quote. 12 month warranty on completed repair work.

You do not need to identify your doorset first.

You do not need to identify your doorset before getting in touch. Many bifold doors are unbranded or contain a combination of components from different manufacturers. Identifying the system, cross-checking component and part availability, and sourcing suitable parts through our established European network of suppliers is our job. Pro-Lock regularly repairs bifold door systems that other repairers have classed as obsolete, where a suitable repair route can be identified.

Warranty

All work carried out is backed by our market-leading 12 month warranty, covering our workmanship and any parts supplied and fitted as part of the repair where applicable.

Recent repairs on Siegenia hardware

A seven-panel uPVC doorset on Siegenia hardware in Dereham was assessed with doors that would not close or lock correctly, traced to the original installation where the double glazed units had not been toe and heeled. See the Dereham repair ↗