uPVC windows dominate the UK market due to their durability, low maintenance, and excellent thermal performance. However, after years of continuous use, even the highest quality uPVC windows can develop common problems. These issues often relate to mechanical failure, rather than the frame itself, meaning a uPVC repair specialist can often restore full function for far less than the cost of replacement.
Problem 1: The dropped sash and alignment issues
This is perhaps the most common uPVC problem. The sash (the opening part) appears to have “dropped” slightly on the handle side, making it rub against the frame at the bottom or top when you try to close it.
1. Why the sash drops
The sash is heavy and is held in place by friction and the hinges. Over time, particularly on large, heavy windows (like bathroom obscures or large tilt-and-turn units), gravity can cause the sash to settle. This creates misalignment, preventing the multi-point locking mechanism from engaging correctly.
2. How to fix dropped uPVC window
- Hinge Adjustment: Modern uPVC sashes are fitted with small hexagonal adjustment screws on the hinges. A professional fitter will use an Allen key to turn these screws, which physically pulls the sash back into the correct square alignment within the frame.
- Packing: If adjustment isn’t enough (or if the seal is failing), the fitter may need to “toe and heel” the unit. This involves inserting specialist plastic glazing packers into the frame under the glass unit in specific corners to force the sash back into square. This requires specialist knowledge to ensure the glass remains fully supported.
Problem 2: Multi-point lock failure and jammed handles
The multi-point locking system is the heart of uPVC window security. It uses a handle to drive a central mechanism that extends bolts or mushroom cams at multiple points around the frame.
1. Faulty lock mechanism
If the handle spins freely or the key doesn’t turn the bolts, the internal gearing may have seized or snapped.
- Repair vs. Replacement: A skilled uPVC specialist will attempt to lubricate or replace the internal gearing strip (the espag) without needing to replace the entire window.
2. Jammed handle
Often, a handle is jammed when the window is left slightly ajar and the locking mechanism attempts to engage—this is the anti-slam device kicking in.
- The fix: The fitter will bypass the anti-slam mechanism to reset the handle. This is a common service that avoids unnecessary lock replacement.
Problem 3: Draughts and failed seals
If you feel a draught or see condensation forming between the two panes of glass, you have a different issue.
1. Failed glazing unit seal (Between the glass)
Condensation between the panes means the hermetic seal around the double-glazed unit has failed, allowing moist air to enter.
- The fix: The entire glass unit (the IGU – Insulated Glass Unit) must be replaced. The frame itself is sound, and a fitter can simply replace the glass unit without removing the window frame.
2. Failed sash seal (Draughts)
If air is coming around the edge of the sash, the rubber gasket seals are likely perished, hardened, or compressed.
- The fix: A professional can remove and replace these seals with new rubber gaskets, immediately restoring the draught-proofing performance.
Hiring a professional for uPVC work saves you money by preventing unnecessary window replacement and is the quickest route to restoring the security and efficiency of your home.
With Rated People, you have the power to get it done. Find a trusted, local tradesperson today.
