A uPVC door that sticks, drags, or allows a noticeable draught is often caused by the natural settling of the house structure, thermal expansion, or wear over time. These performance problems rarely require professional intervention and can usually be resolved with a straightforward adjustment. Understanding the door’s mechanics allows you to restore smooth operation and maintain the energy efficiency it provides. This guide details the precise adjustments needed to bring your door back to its optimal fit.
Identifying the Need for Adjustment
Diagnosing the specific problem dictates which adjustment mechanism to target. Common symptoms include the door panel dragging or sticking against the threshold or frame. Draughts or rattling indicate an air gap has formed between the door and the frame, compromising the seal. Difficulty locking the door, such as a stiff handle or a key that will not turn easily, suggests a misalignment between the door’s locking points and the frame’s keeps.
To pinpoint the misalignment, slowly close the door and observe the reveal, which is the gap between the door sash and the outer frame. An uneven reveal confirms the door has dropped or shifted. Gather the necessary tools, typically including 4mm or 5mm hexagonal (Allen) keys and a Phillips head screwdriver. Although hinge types vary, the underlying principles of adjustment—Vertical, Lateral, and Compression—remain consistent across most modern uPVC systems.
The Three-Axis Hinge Adjustment
Most alignment issues are corrected by manipulating the door’s position along the three axes of movement controlled by the hinges. The most important rule is to make small, incremental changes, turning adjustment screws by no more than a quarter or half turn at a time. This measured approach prevents over-adjustment, which can compound the problem. After each minor adjustment, close and test the door to assess the effect before proceeding further.
Vertical Adjustment
The Vertical Adjustment moves the door up or down within the frame, fixing issues where the door drags on the bottom threshold or scrapes the top of the frame. This adjustment is typically controlled by a screw located at the top or bottom of the hinge body, often concealed beneath a plastic cap. Turning the screw clockwise raises the door panel, while turning it counter-clockwise lowers it. When adjusting, work on all hinges equally, starting with the top hinge, to distribute the door’s weight evenly across the frame.
Lateral Adjustment
The Lateral Adjustment moves the door side-to-side, correcting issues where the door panel rubs against the frame on either the hinge side or the lock side. The lateral adjustment screw is usually found on the side of the hinge body, accessible when the door is open. Turning this screw moves the door sash closer to or further away from the hinge side, often allowing up to 5mm of movement. This adjustment centers the door within the frame to ensure an even reveal along the lock side.
Compression Adjustment
The Compression Adjustment controls the pressure with which the door panel seals against the frame, directly addressing draughts and rattling. This mechanism pulls the door sash tighter into the frame, ensuring the weather seals are engaged. The compression screw is sometimes a separate component or integrated into the main hinge body, often requiring a 4mm Allen key. Increasing compression eliminates air gaps, but avoid over-tightening, as this can make the handle difficult to lift or the door hard to close.
Aligning the Lock and Latch Mechanism
Once the door panel is aligned using the hinge adjustments, the final step is fine-tuning the lock side for smooth operation and sealing. The main latch, the spring-loaded bolt that holds the door closed, engages with the strike plate on the frame. If the latch is catching, loosen the screws holding the strike plate and shift its position slightly up, down, or in, before re-tightening. This ensures the latch glides into the keep without resistance.
The multi-point locking system relies on keeps on the frame and cams or rollers on the door edge. Many modern uPVC doors feature eccentric cams, which are off-center rollers rotated with an Allen key to adjust compression. Rotating these cams changes the distance they project from the door edge, allowing you to increase or decrease the tightness of the seal against the frame keeps. This is an effective method for eliminating persistent draughts remaining after hinge compression adjustment.
The metal keeps on the frame, which receive the locking bolts and hooks, can also be adjusted slightly to ensure alignment with the door’s locking points. After all adjustments are complete, test the door by closing it, lifting the handle to engage the multi-point locks, and turning the key to ensure the mechanism operates without strain. As a final maintenance step, apply a silicone-based lubricant to the hinges and the internal lock mechanism to maintain smooth function and prevent future sticking.