uPVC window repair
Hinges, handles, friction stays, seals and misaligned sashes — restoring smooth operation and better draught-proofing.
Repairs & upgrades
Fixed at the source.
Not replaced by default.
A window that won’t close, a door that drags, a misted pane. Most faults are diagnosed on the first visit and fixed without the cost of a full replacement.
Repair or replace?
An honest assessment first.
A failed hinge, a worn gasket or a misted glass unit can all be swapped out while the frame stays in place.
Less mess, less waste and a much smaller bill — and it keeps perfectly good frames out of landfill. If a repair will last, we'll tell you. If replacement genuinely makes more sense, we'll explain why and quote for both. No pressure, no upselling.
What we repair
Every product we install — and plenty we didn't.
Double glazing repairs
Failed or misted sealed units replaced without replacing the frame, with the option to upgrade to energy-efficient glass.
Window lock repair
Jammed locks, snapped handles, seized shoot bolts and worn keeps. High-security replacement locks available.
Automatic door repairs
Sensor, motor, drive, track and control faults on sliding and swing doors, with planned maintenance contracts.
Roof light repairs
Leaks, water ingress, cracked or misted glazing, failed seals, condensation and ventilation issues.
Double glazing door repairs
Locks, barrels, handles, dropped doors, rollers, tracks, seals and glazing — on uPVC, aluminium, composite, bi-fold and sliding doors.
Book a repair assessmentOn every job
What we actually deliver.
- 01
Free assessment
We inspect, diagnose and quote before any work starts.
- 02
Honest pricing
Clear, fixed quotes with no hidden call-out surprises.
- 03
Quality parts
Locks, hinges and glass units from trusted UK suppliers.
- 04
Local response
Based in Thornton Heath — Norbury, Purley, South Norwood, Mitcham, Streatham and beyond.
Questions
Good to know.
Can misted double glazing be repaired without replacing the window?
Yes. Misting means the sealed unit has failed, not the frame. We replace only the glass unit inside your existing frame, restoring clear views and insulation.
Do you repair window locks the same day?
In most cases, yes. Our technicians carry a wide range of common locks, handles and mechanisms, and security-related faults are treated as priority calls.
Do you repair automatic doors for commercial premises?
Yes — automatic sliding and swing doors for shops, offices and commercial buildings, covering sensors, motors, tracks and control units, with planned maintenance contracts.
What are the signs my roof light needs repairing?
Water stains around the frame, condensation trapped between panes, draughts or visible cracks. A simple reseal today can prevent structural water damage later.
Free design consultation
Tell us about your project.
No pressure, no obligation. We'll talk through proportion, profile, colour and glass, then arrange a survey if you'd like to go further.
- Call020 3835 2583
- Mobile / WhatsApp07925 678210
- Emailinfo@4moonwindows.co.uk
- HoursMon–Fri · 08:00–17:30
Request received
Thank you.
A member of the 4Moon team will call you back to arrange your free design consultation. If it's urgent, call us on 020 3835 2583.