When a double glazed unit goes misty or 'blows', it means the rubber seal around the edge has perished and allowed moisture to creep in between the two panes. Once condensation appears inside the glass, no amount of cleaning on the outside will shift it — and the window loses much of its thermal insulation too.
The good news is that you almost never need a brand new window. We simply remove the failed sealed unit and replace the glass itself, leaving your existing frame, handles, hinges and locks untouched. It's the smart way to fix misted double glazing: quicker, far cheaper than a full replacement, and you'd never know the unit had been changed.
We've been carrying out blown double glazing repair and double glazed unit replacement across Wilmslow, Alderley Edge, Knutsford, Handforth and the wider Cheshire area for over 20 years. Most jobs are completed in two short visits: we measure up, order your new unit from our local manufacturer, then return to fit it — usually within a week or two.
Whether you need to replace a single failed unit in a bedroom or every blown glass unit in the house, we give you a fixed, no-obligation quote before any work starts. All replacement sealed units come with a 10-year guarantee and A-rated energy efficiency as standard.
- Misted double glazing repair & blown unit replacement
- Free, no-obligation quote - usually within 24 hours
- All replacement units carry a 10-year guarantee
- A-rated energy efficient glass fitted as standard
- Toughened, laminated, obscure & Georgian bar options
- We tidy up - no mess left in your home or garden
- Most units fitted within 7-14 days of measuring
Frequently asked
What is misted double glazing repair?+
Misted double glazing repair means replacing a failed sealed unit where condensation has formed between the two panes of glass. We remove the old unit and fit a new one, leaving your existing window frame in place.
What is blown double glazing repair?+
'Blown' is the common term for a failed double glazed sealed unit. Moisture has breached the rubber seal and got trapped between the panes, causing misting or fogging that cannot be wiped away. We replace the blown glass unit with a brand new sealed unit.
Can you fix condensation between double glazing panes?+
Yes - condensation trapped between the panes means the sealed unit has failed. The only permanent fix is to replace the glass unit itself. We measure, manufacture and fit a new unit that restores clarity and insulation.
Do you replace failed double glazed units?+
Absolutely. Replacing failed double glazed units is our most common job. We keep your existing frame and just swap the glass, which is 60-80% cheaper than a full window replacement.
How much does it cost to replace a blown glass unit?+
It depends on size and glass type, but replacing a blown glass unit is surprisingly affordable - usually a fraction of the cost of a whole new window. We provide a fixed-price quote with no hidden extras.
How long does double glazed unit replacement take?+
Fitting takes 20-40 minutes per window once the unit is made. We measure on our first visit, manufacture your new unit, then return to fit it - usually within 7-14 days.