Therma-Tru Window Replacement Nationwide | Winslow Windows & Doors

Therma-Tru Window Replacement: The Coral Gables Owner’s Guide

Therma-Tru window replacement in Coral Gables typically runs $450 to $1,200 per window installed, depending on the series and whether you’re replacing a sash, glass pack, or full unit. We stock common Therma-Tru-compatible parts on our trucks, and most replacements can be completed the same day we arrive. The way most Coral Gables homeowners discover a Therma-Tru part has failed is subtle: a window that no longer locks flush, condensation you can’t wipe away, or a frame that suddenly binds when you crank it open.

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Therma-Tru earned its reputation building fiberglass entry doors, and their window lines carry that same DNA: dense composite frames, multi-point locking hardware, and sashes engineered for visible light and clean sightlines. When a Therma-Tru component fails, you don’t just want a handyman with a generic part. You want someone who knows why the balance shoe on a Therma-Tru double-hung wears differently than a vinyl knockoff, and who can tell a Series 300 sash from a Benchmark window at a glance.

Which Therma-Tru Models This Applies To

We service and replace parts across the Therma-Tru product range: the Performance Series (double-hungs, casements, sliders), the Benchmark line, and the older Signature Series still found throughout Coral Gables’ Mediterranean and ranch homes. Here’s the compatibility gotcha most owners miss: Therma-Tru components are series-specific, not universal. A balance shoe from a Performance double-hung won’t seat properly in a Signature series frame, even if the visible dimensions look close. We’ve pulled too many “universal” parts off our truck that were anything but.

How to identify your model: open the sash and look for the etched laser code on the glass spacer, typically in a bottom corner. It reads something like “TT-300-DH” followed by a manufacture date. The frame header usually carries a paper label from the original install. If both are gone, we measure the sash profile thickness and the balance channel depth to determine the series. As for OEM versus aftermarket: for visible hardware like locks and cranks, OEM Therma-Tru is worth the premium because the finish and screw patterns match perfectly. For internal components like balances and weatherstripping, a high-grade aftermarket equivalent often performs as well or better in Florida humidity, at 30 to 40 percent less.

A note of clarity: Winslow Windows & Doors is an independent, locally owned company. We’re not affiliated with Therma-Tru, but we’ve installed and serviced their product line for over a decade across Coral Gables. We also carry compatible parts for PGT, CGI, and CWS windows, so if you have a mixed house, one call covers it.

Signs Your Therma-Tru Window Replacement Is Failing

• Condensation trapped between the panes. The insulated glass unit’s seal has failed. Once argon or krypton leaks out and humid Florida air gets in, the view gets foggy and the window’s energy performance drops. This is a glass-pack replacement, not a full window job.
• Lock and keeper misalignment. Over years of use and frame settling in Coral Gables’ limestone-heavy soil, the sash drifts a few millimeters. The lock won’t throw, the window never fully seals, and your A/C dollars leak out. We realign or replace the hardware and shim the frame.
• Balance failure on double-hungs. You lift the sash and it won’t stay up, or it slams down without warning. The balance springs or block-and-tackle system has worn out. This is a safety issue, especially for kids and older homeowners, and it’s one of the most common Therma-Tru repairs we do.
• Visible frame warping or stress cracks at the corners. South Florida’s heat and humidity punish composite frames over a decade. Hairline cracks at miter joints signal the weather barrier is compromised. Depending on severity, we replace the sash frame or the full unit.
• Hard-to-turn casement cranks. Grease dries out, worm gears strip, and coastal salt air accelerates the wear. A crank that fights you is about to fail completely. Replacing the operator mechanism is a 30-minute fix when you have the part.

Replacement Cost & What’s Included

Here’s what Coral Gables homeowners should expect to pay for Therma-Tru window replacement, installed:

• Weatherstripping and seal replacement: $95 – $165 per window
• Lock and keeper hardware (OEM Therma-Tru): $140 – $220 per window
• Sash replacement (single sash, common sizes): $285 – $425 per sash
• Insulated glass pack replacement: $350 – $550 per window
• Full window unit replacement (including frame and install): $850 – $1,900 per window, depending on size, series, and whether it’s impact-rated

What drives the range: glass type (laminated impact glass adds $200 to $400 per unit), window size, and whether we’re matching an existing architectural profile or doing a clean new opening. Every quote includes labor, haul-away of the old unit, and our workmanship warranty. No change orders, no “we found rot” surprises. The price we quote is the price you pay. If you have a written estimate from another company, bring it to us for a free second opinion.

DIY or Call Us?

Let’s be honest about what’s safe and what isn’t. You can absolutely replace a casement crank operator or snap in new weatherstripping yourself, if you can find the right Therma-Tru part and you have basic tools. But balance systems on double-hungs are under constant spring tension, and a mis-seated balance shoe can fire out of the channel with enough force to break a hand. Glass pack replacement requires proper shimming, sealing, and a level you can trust. And full unit swaps involve flashing details that matter in hurricane country.

If you’re in Coral Gables and the fix is more than hardware, call us at (904) 478-8983. We’ll come out, assess the window, and tell you exactly what needs replacing and what doesn’t. Free estimate, no trip charge in the county, and no pressure. Ed Winslow has spent more than two decades working on South Florida windows, and he grew up just up the road near the Biltmore. He knows what this climate does to a window because he’s seen it on thousands of them.

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