Thermopane Window Restoration

Fog or condensation between the panes of a double-glazed window means the sealed unit has failed. Overhaul provides thermopane window restoration for homeowners across Ottawa, Stittsville, Kanata, Nepean, Barrhaven, and Orleans. We replace the failed glass unit inside your existing window frame, eliminating the fog and restoring full insulating performance without the cost of a complete window replacement.

What Causes Foggy Windows?

Double-pane and triple-pane windows rely on a sealed air space between the glass to insulate your home. Over time, the perimeter seal can break down due to temperature cycling, UV exposure, age, or manufacturing defects. Once the seal fails, moisture enters the air space and condenses on the interior glass surfaces. The result is a cloudy, hazy, or streaked appearance that cannot be cleaned because the moisture is trapped between the panes.

A failed seal also means the insulating gas between the panes has escaped. Even if the fog is not immediately visible, a compromised seal reduces the thermal performance of the window, leading to drafts, cold spots, and higher heating costs during Ottawa winters.

Restoration, Not Replacement

Many homeowners assume that foggy windows mean the entire window needs to be replaced, frame and all. In most cases, that is not true. The frame, hardware, and operating mechanism are often in perfectly good condition. The problem is limited to the sealed glass unit itself.

Thermopane restoration involves removing the failed sealed unit from your existing frame and replacing it with a new, factory-sealed unit matched to the correct dimensions and glass specifications. Your window frame stays in place. Your interior and exterior trim stays intact. There is no need to resize the opening, repaint, or refinish surrounding surfaces.

This approach costs significantly less than a full window replacement and preserves the original look and function of your windows. For homeowners with well-maintained frames, it is the most practical and cost-effective solution.

Signs Your Thermopane Needs Restoration

You may need thermopane restoration if you notice any of the following:

• Fog or haze between the panes that does not clear when you clean the glass
• Condensation or water droplets visible inside the sealed unit
• A milky or cloudy film that worsens in certain weather conditions
• Visible streaks or mineral deposits between the glass surfaces
• Drafts or cold spots near windows that previously performed well

These symptoms typically start in one or two windows and spread to others over time as seals of the same age begin to fail. Addressing them early prevents further energy loss and avoids the need for more extensive work down the road.

What to Expect

1. Contact us with a description of the problem. Photos of the affected windows help us prepare for the visit.
2. On-site inspection. We assess each window individually to confirm seal failure and check the condition of the frame and hardware.
3. Sealed unit replacement. We remove the failed unit and install a new factory-sealed thermopane matched to your window specifications.
4. Final inspection. Every restored window is checked for proper fit, seal integrity, and smooth operation before we leave.

Most thermopane restorations are completed in a single visit. For homes with multiple affected windows, we can schedule the work in stages to suit your availability.

Our Thermopane Warranty

Every thermopane restoration is backed by our 12-year transferable warranty against seal failure, including labour. The warranty transfers to new homeowners if you sell your property, adding value at resale. This is one of the longest warranties available in the Ottawa market for sealed unit replacement.

Working With Older or Heritage Windows?

Homes with older wood-framed or heritage windows can also develop seal failures, but the restoration approach may differ depending on the frame condition and glass profile. If your home has heritage or character windows, visit our Heritage Window Restoration page for details on how we handle those projects.

Serving Ottawa and Surrounding Communities

Overhaul provides thermopane window restoration across Ottawa, Stittsville, Kanata, Nepean, Barrhaven, and Orleans. We come directly to your home to assess and complete the work on-site, so there is no need to remove windows yourself or arrange transportation.

With over 40 years of hands-on experience in window refurbishing and restoration, our technicians understand the full range of window types, frame materials, and sealed unit configurations found in homes across the Ottawa region.

Foggy windows? Let us take a look.

Call us at (613) 869-1200 or contact us online to schedule an assessment.

For a full overview of our window services, visit our Window Refurbishing page, or check our FAQ for answers to common questions.