Problems with double glazing rarely happen overnight. In many cases, performance declines gradually, which makes it easy for homeowners to miss early warning signs. Addressing issues early can help maintain comfort, reduce energy waste and avoid unnecessary full window replacements.
Common signs that your double glazing is no longer performing properly
Double glazing is designed to improve insulation, reduce noise and enhance security. Over time, seals, frames and hardware can deteriorate, especially in properties exposed to regular temperature changes and everyday use.
Condensation between the glass panes
Moisture trapped inside the sealed unit is one of the clearest signs that double glazing has failed. This happens when the internal seal breaks and allows damp air to enter the space between panes. Once this occurs, the insulating gas escapes, reducing thermal performance and making the window far less effective. The issue cannot be resolved with ventilation or cleaning and normally requires professional glass replacement.
Draughts and noticeable temperature changes
If rooms feel colder near windows or you notice draughts despite windows being closed, this often points to worn seals or frame movement. Even small gaps allow heat to escape, which can have a significant impact on comfort during colder months. Over time, this increased heat loss may place extra strain on your heating system.
Windows no longer open or close smoothly
Double glazed windows should operate easily. If you experience stiffness, jamming or misalignment, it may indicate warped frames, worn hinges or lock issues. These problems can worsen if ignored, increasing the risk of security issues and accidental damage to the glass.
Cracks, chips or visible damage to the glass
Any visible damage should be taken seriously. Cracked or chipped glass weakens the structure of the unit and increases the risk of further breakage. It also affects insulation and safety, particularly in homes with children or pets. In many cases, replacing the damaged pane is quicker and more cost effective than waiting for complete failure.
Increased outside noise entering your home
One of the main benefits of double glazing is sound reduction. If external noise becomes more noticeable, it may indicate failing seals or gaps around the frame. This is often overlooked but can be a clear sign that the window is no longer performing as intended.
Frames showing signs of wear or movement
Older window frames may show signs of swelling, cracking or movement, particularly in timber or ageing uPVC units. Frame issues can affect how well the glass sits within the window and may lead to recurring seal failures if not addressed properly.
Unexpected increases in energy bills
Failing double glazing can quietly contribute to higher heating costs. If your energy bills rise without changes in usage or tariffs, inefficient windows may be allowing heat to escape. Repairing or replacing damaged units can help restore insulation and improve overall energy efficiency.
Mould or damp forming around window edges
Persistent moisture around window frames can encourage mould growth, particularly in colder rooms. While condensation can sometimes be linked to ventilation, repeated damp patches around double glazing often suggest seal or frame problems that need professional attention.
Need professional double glazing repairs in Manchester, Birmingham and Nottingham?
Hunters Glass Ltd provides experienced glaziers in Manchester, Birmingham and Nottingham, offering honest assessments and dependable double glazing repairs. If your double glazing is showing signs of wear, call us today on 03301331655 or complete our contact form to arrange an inspection and restore your windows to proper working condition.
