How to Know That Your Double Glazing Has Failed in Your Leicester Home
Spotting double glazing failure early can save you money on energy bills, repairs, and full window replacement. In Leicester homes, where windows face wet winters and cold draughts, misted panes and leaks are everyday headaches for many households.
Well-installed double glazed windows should comfortably last 20-35 years. But over time, seals fail, frames warp, and glass cracks. We’ve pulled this guide together from years of hands-on repairs at Phair Windows, serving Leicestershire since 1998.
Here’s how to spot problems fast, understand the causes, and know when to call our experts for window repair or replacement.
5 Common Signs of Double Glazing Failure
Ignoring these early clues often leads to bigger problems (and costs). Here’s what to look for and feel in your home.
1. Misted or Foggy Panes
Condensation trapped between the glass panes is the classic giveaway that your airtight seal has failed, allowing moisture to seep in and ruin your view.
- On the inside surface – Often down to high indoor humidity – combat it with better ventilation, a dehumidifier, or trickle vents.
- On the outside surface – Reassuringly normal! It shows your windows are holding heat inside effectively.
- Between the panes – Serious issue. The unit’s “blown,” and no DIY drill-and-dry hack will fix it long-term – professional replacement is essential.
Related: How to Fix Misted Double Glazing
2. Draughts Around the Frame
A persistent chill near your windows, even when shut tight? Worn rubber seals or gaps in the frame are letting cold air infiltrate, making rooms feel uneven and uncomfortable.
Easy at-home test: Light an incense stick and hold it near the frame on a breezy day. If smoke wafts inwards, you’ve got leaks. Common in older uPVC installs around Leicester.
Related: Stop Draughts on uPVC Windows
3. Energy Bills Creeping Up
Same household habits, but your gas or electric costs jump unexpectedly? Failing insulation means heat leaks out faster, forcing your heating to run non-stop.
Benchmark: New double glazing can cut heating costs by 10-20%. If yours isn’t performing, it’s costing you.
Related: Do New Windows Save Energy?
4. Water Leaks Through Frames
Puddles inside from the window itself (not sideways rain)? Pinpoint the source:
- Cracked weather seals – Years of exposure degrade the rubber edging.
- Clogged drainage – Silt, leaves, or algae block sill weep holes – a quick clean often sorts it.
Ignore this, and you’ll face damp walls, mould growth, or worse. Prevention starts with regular checks.
5. Cracked, Chipped or Scratched Glass
Surface scratches polish out easily, but deeper damage spells trouble:
- Small chips – Resin fillers work for shallow ones.
- Cracks to the frame– They spread with heat/cold cycles, inviting water and weakening security.
4 Root Causes of Double Glazing Failure
Understanding why helps you act smart:
- Seal Deterioration – Rubber seals shrink/crack after 10-20 years exposure
- Poor Installation – Gaps from bad fitting let in air/moisture from day one
- Thermal Stress – Glass expands/contracts with extreme hot/cold cycles
- Frame Movement – House settling misaligns frames, stressing seals
How To Prevent Double Glazing Problems
Here are some tips to keep your double glazing performing its best year-round:
- Inspect yearly – Check seals, hinges, drainage for wear
- Ventilate – Use trickle vents, avoid drying clothes indoors
- Clean properly – Mild soap on frames, no harsh chemicals
- Lubricate – Silicone spray on handles and stays prevents sticking.
Repair vs Replace: What’s Best?
If your windows are showing signs of double glazing failure, use this table to find the best fix:
| Issue | Quick Fix Possible? | Recommended Action |
|---|---|---|
| Misted panes | No | Replace sealed unit |
| Minor draughts | Sometimes | New seals (£100-£200) |
| Leaks | Often | Clean seals/drainage |
| Cracked glass | Depends on size | Usually full replacement |
| Multiple failures | No | New windows |
Most economical: If windows are 20+ years old, we recommend replacing the full unit with our A++ rated windows.
Expert Double Glazing Repairs in Leicester
Phair Windows has repaired and replaced thousands of double glazed units across Leicestershire since 1998. We can help with window repairs, and full window replacements.
Our process:
- Free home survey – No obligation, we diagnose the exact problem
- Transparent quote – Repair or replace options
- Fast install – Usually 1-2 days, minimal disruption
- 10-year guarantee – Peace of mind
Call 0116 456 0242 or book your free quote online today.
FAQs
When double glazing fails, issues like condensation, drafts, and reduced energy efficiency arise, impacting comfort and increasing energy bills. Timely repair or replacement is necessary.
Yes, failed double glazing can often be repaired, depending on the extent of the damage. Repairs might involve fixing seals, replacing glass, or addressing other issues to restore functionality.
You can tell if double glazing has blown by noticing condensation or fogging between the panes, reduced insulation, and possible drafts. A professional assessment is recommended for accurate diagnosis and solutions.
Home insurance coverage for failed double glazing varies. Some policies might cover accidental damage or certain perils, while others may require specific add-ons or endorsements. Check your policy terms for clarity.
Related Articles:
- Should New Windows Have Condensation on the Inside?
- How Effective is Double Glazing at Reducing Noise?
- How to Fix Blown Double Glazing & Clear Misted Windows
- How to Tell the Age of Double Glazing
- Cost of Double Glazing a 3 Bed House UK
- How Long Does Double Glazing Last?
- 10 Double Glazed Windows Benefits
- Cost of Double Glazed Sash Windows
- Will New Double Glazed Windows Save Energy?
- Do Trickle Vents Help Stop Condensation?
