What’s Happening

Drafty windows that push your energy bills up almost always point to one thing: the seal between your window and the outside air has failed. That failure lets conditioned air escape and unconditioned air push in, and your heating or cooling system runs longer to compensate. Call (903) 354-7134 for a free written estimate – your local Westlight Windows & Doors team can usually pinpoint the cause on the first visit.

Call (903) 354-7134

The good news is that a window draft has a small number of causes, and most of them are visible once you know what to look for. Worn weatherstripping, failed glass seals, settling frames, and damaged sash hardware each leave their own fingerprints. The sections below walk you through each one so you can tell your technician exactly what you’re seeing before anyone shows up – and so you’re not left guessing whether this is a $40 fix or a full replacement.

Why It Happens

Weatherstripping Failure

Weatherstripping is the soft material – foam, felt, or rubber – that runs along the edges of a window sash and forms a seal when the window closes. It compresses and bounces back thousands of times before it gives out, and when it does, it either flattens permanently or cracks and pulls away from the frame. You can check it yourself: close the window on a piece of paper and try to pull it out. If it slides out easily, the seal is gone.

Failed Insulating Glass Unit (IGU) Seal

Most modern windows use two or three panes of glass bonded together with a sealed air gap in between – that gap is what gives the unit its insulating value. When the seal around that gap breaks, outside air gets in between the panes, and the unit loses most of its thermal performance. The clearest sign is fogging or condensation trapped between the panes that you can’t wipe off from either side.

Frame and Sash Warping or Settlement

Wood and composite frames absorb moisture over years and can warp just enough to leave a gap that no weatherstripping can fully bridge. Vinyl frames are more stable but can rack if the rough opening shifts with settling. If your window closes but never feels fully tight – or if you can see daylight along the frame edge – warping or settlement is the likely culprit.

Damaged or Misaligned Hardware

Casement and awning windows depend on their locks and latches to pull the sash tight against the frame. If the handle feels loose, won’t crank fully closed, or the sash visibly gaps on one side when latched, the hardware is the problem – not the seal itself. This is one of the few draft causes where a repair rather than a replacement might be all that’s needed, though it depends on the age and condition of the overall unit.

What to Do Right Now

• Run the hand test on every suspect window. On a windy day, hold your hand near the edges of the closed sash, the corners, and along the meeting rail. You’re looking for the coolest spots – that’s where air is moving through.
• Look for daylight. Turn off the lights in the room, close the blinds, and check the perimeter of each window frame. Any visible daylight means a gap that needs attention.
• Photograph what you find. A photo of fogged glass, cracked weatherstripping, or a visible gap in the frame gives your technician useful information before the visit and keeps the conversation specific.
• Don’t tape over the gaps as a long-term solution. Temporary weatherstrip tape and caulk rope can stop the bleeding for a week, but they can also trap moisture if applied over a failed seal. Note what you did so the technician knows what’s underneath.
• Check the trim and caulking line on the exterior, but stay on the ground. If exterior caulk is cracked or missing around the window frame, that’s a real entry point for air. Do not climb a ladder to inspect second-story windows or above – photograph from below and let a uniformed technician handle anything at height.

How We Fix It

When your local Westlight Windows & Doors technician arrives, the first thing that happens is a hands-on inspection – not a sales pitch. They’ll check the sash seal, the frame perimeter, the glass unit, and the hardware before saying anything about cost. At that point, you get a written price before any work starts. That’s not a formality; it’s the Kingswell Way, and it’s how every job works.

If the weatherstripping or hardware is the issue, the fix is usually straightforward and completed the same visit. If the glass unit’s seal has failed, the solution is typically a window replacement – and your technician will walk you through the product options from our eight manufacturer lines, including energy-efficient ECO Window Systems and impact-rated PGT, so the window that goes in is the right one for your home and climate, not just whatever happens to be on the truck.

The finished job is covered by our 365-Day Done Right Promise: if it’s not right within the guarantee period, we come back and fix it at no charge. That promise is in writing, handed to you when the job is complete.

Frequently Asked Questions

Get It Fixed

Your local Westlight Windows & Doors team is ready to take a look. Call (903) 354-7134 anytime – a real person will answer – or book online. You’ll get a written price before any work starts, and the job is backed by our 365-Day Done Right Promise.

Written by Owen Satterfield, Owner at Westlight Windows & Doors, serving communities nationwide as part of the Kingswell network since 2009.