Repairing Double Glazed Windows When Double-glazed windows "blow" they let the gas that insulates them, argon, escapes, causing them to reduce their energy efficiency. The good news is that blown double glazing is often repaired without the need to replace the windows. Condensation or moisture in between your double-glazed windows https://www.repairmywindowsanddoors.co.uk/redbridge-windowrepair/