What the stiffness is telling you
On a UPVC or composite door, lifting the handle is what drives the multi-point mechanism: hooks, rollers and shootbolts move up and down the strip and engage keeps in the frame. Turning the key then locks it all in place.
When lifting gets hard, something in that chain is fighting you. There are four usual culprits, and they feel slightly different.
1. A worn centre gearbox
The gearbox converts your handle movement into the mechanism’s movement, so it takes essentially all of the load in the system. It’s the most common failure point on Irish doors.
How it feels: progressively harder over weeks or months, sometimes with a grinding or crunching sensation. Eventually the handle either flops uselessly or jams solid.
The fix: replace the gearbox. On most doors this doesn’t require a whole new mechanism, and it’s the job our UPVC door lock repair service does most often.
2. A dropped or misaligned door
Doors settle. A few millimetres of drop means the hooks no longer align with the keeps, so every lift is forcing metal past metal.
How it feels: you can lift the handle easily when you pull or lift the door slightly, and not otherwise. That test is diagnostic on its own.
The fix: adjust the hinges and keeps. Often no parts at all, and it prevents the gearbox failure that would otherwise follow.
3. A dry mechanism
Multi-point mechanisms need occasional lubrication on the moving points along the strip. Neglected for years, they stiffen.
How it feels: uniformly heavy but smooth, without grinding, and slightly better in warm weather.
The fix: clean and lubricate. Cheap, and worth doing annually.
4. Weather and seasonal movement
Damp and cold make everything above worse. This is why our UPVC calls spike from October onwards — the underlying problem existed all summer and the weather pushed it over the line.
Why forcing it is the expensive choice
The gearbox is a mechanical part with a finite tolerance. Every hard lift takes some of that away.
The pattern we see repeatedly: stiff in September, harder in October, “you have to know the knack” in November, completely seized in December — usually on a morning when someone needs to leave for work.
An adjustment at the stiff stage typically costs €80 to €130. A gearbox replacement after it shears is €130 to €200. It’s the same door, months apart, and the only difference is whether it was dealt with early.
The two-minute test
Open the door fully and lift the handle with the door hanging free. If it lifts smoothly, your mechanism is fine and the problem is alignment. If it’s stiff even with the door open, the mechanism itself needs attention.
That test tells you which conversation to have, and it costs nothing.
What we do
Diagnose the real cause first — gearbox, alignment, hinges or lubrication — then repair what’s actually failed. We carry common gearboxes and mechanisms on the van, so most repairs finish in one visit, and any door we work on gets realigned as part of the job so the new part isn’t fighting the frame from day one.
Patio and sliding doors have their own version of these problems, covered in our guide on patio and sliding door lock faults.