Diagnose · decide · get help
Not every window fault means a full replacement. Tell the symptom apart from the cause, see whether it is a quick repair or a bigger job, and book a free, no‑obligation assessment with a local installer.
Start here
Most window faults fall into a handful of patterns. Find yours below to see the likely cause — and whether it is usually a repair or a replacement job.
A cold edge or whistling gap usually means a perished seal or gasket — often a straightforward repair rather than a new window.
See draughty-window fixes
Spongy, dark or flaking timber can sometimes be repaired — but widespread rot is usually the point where replacement makes more sense.
Check rotten frames
Handles that stick, spin or snap, and hinges that have dropped, are among the most common — and most repairable — faults of all.
Fix locks, handles & hingesThe big question
A blown sealed unit or a worn handle is often a quick fix. Widespread rot, warped frames or ageing single glazing usually point to replacement. Here is the quick way to tell them apart.
No pressure
An assessment is about honest advice, not a hard sell. Here is what happens after you send your details.
Answer the two quick questions above — whether you own the home and your postcode. It takes about a minute.
A vetted installer near you arranges a free, no-obligation assessment of your windows and explains what they find in plain English.
If a repair will do, they will say so. If replacement is the sensible call, you will get like-for-like quotes with funding and contribution options, subject to eligibility and a home survey.
If replacement turns out to be the right move, you can explore funded window and door packages, get like-for-like quotes, or browse replacement options for every home. £0-upfront options may be available for those who qualify — see help with the cost of new windows.
Real results
Assessments and any installation work are carried out by our matched installation partner. Here is how their customers rate them.
Our installation partner, Help 2 Buy Windows, is rated 4.9 out of 5 from more than 12,000 reviews on Trustpilot — the UK’s No.1 double glazing installer. Read the reviews.
The surveyor was straight with me — two of our windows only needed the sealed units swapping, not the whole frame. No hard sell at all, and the front room is warmer and much quieter now.
We had put up with a misted kitchen window for years, assuming it meant new windows all round. It did not. They sorted a long-standing problem in a morning, and the fitters were tidy and cleared up after themselves.
Booked an assessment expecting the worst. They talked me through what was worth repairing and what was not, then fitted the replacements over a single day. The draught by the back door is finally gone.
Guides
Plain-English guides to the symptoms homeowners ask about most — what causes them, and whether they usually mean a repair or a replacement.
Why sealed units fog up, and when a swap fixes it.
Surface, between the glass, or both — tell them apart.
Track down the gap and stop the cold getting in.
Spot early rot and know when timber is past saving.
Stiff, loose or snapped? Most are a simple repair.
The full decision guide, fault by fault.
The tell-tale signs it is time to replace.
Chips, cracks and blown units, explained.
Funding and contribution options, subject to eligibility.
Get a free, no-obligation assessment from a local installer. Failed units get worse through winter — assessments are available in many areas this month.
Get help — free assessment →