Therma-Tru Window Replacement Nationwide | Sightline Windows & Doors Jupiter

Therma-Tru Window Replacement: The Jupiter Owner’s Guide

Therma-Tru window replacement in Jupiter typically runs $340-$780 per opening installed, depending on the series, glass package, and whether the frame is intact. We stock Therma-Tru-compatible sashes, balances, and glazing bead for same-day replacement on most units, and we carry the full line card for orders that need factory lead time. Most Jupiter homeowners discover the problem when a sash won’t stay open, condensation appears between glass lites, or the locking mechanism grinds - signs that the sealed unit or balance system has reached end of life in Florida’s salt-air, high-UV environment.

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Which Therma-Tru Models This Applies To

Therma-Tru’s window portfolio breaks into three series families, and the replacement part you need depends on which line is in your wall.

• Classic-Craft and Fiber-Classic entry door sidelites and transoms: These use a proprietary 1-inch insulated glass unit with a stepped profile that does not interchange with standard 3/4-inch IGUs. The glazing bead is co-extruded with the frame, so prying it without the correct wedge tool cracks the vinyl.
• Therma-Tru vinyl window series (VinylMax and comparable builder lines): These use a constant-force balance system in the jambs, sized by sash weight in pound increments. The balance shoe is stamped with a two-digit code - 14 for a 14-pound sash, 22 for 22-pound, and so on. Matching this stamp is non-negotiable; a 16-pound balance in a 22-pound sash will creep closed within a week.
• Therma-Tru patio door rollers and tandem assemblies: The adjustable tandem roller used in 6-foot and 8-foot sliding panels has a 1-1/4-inch wheel diameter on pre-2019 units and a 1-1/2-inch wheel on current production. The mounting bracket hole pattern changed between generations, so we measure on-site before ordering.

We are an independent service provider with no affiliation to Therma-Tru Corporation. We source OEM parts through our distributor network and also stock quality aftermarket equivalents where the spec matches - the decision is documented on your written quote, not made in the truck.

Signs Your Therma-Tru Window Replacement Is Failing

• The sash drifts or slams shut. This means the constant-force balance has lost tension, usually from corrosion at the balance shoe where Florida humidity enters the jamb pocket. On coastal Jupiter homes within a mile of the Intracoastal, we see this at 8-12 years instead of the inland 15-year norm.
• Fog or moisture between glass panes. The edge seal on the insulated glass unit has failed, allowing moist air into the airspace. Once the desiccant saturates, the fog becomes permanent. The glass unit must be replaced; defogging sprays do not restore the low-E coating or argon fill.
• The lock tongue won’t engage or grinds. The keep (strike plate) has shifted due to frame expansion, or the multipoint lock mechanism has corroded internally. Forcing the handle bends the cam and converts a $45 keep adjustment into a $220 lock replacement.
• Visible daylight around the sash when closed. The weatherstrip has compressed past recovery or the sash has sagged on a worn balance, breaking the compression seal. Your cooling load rises before you notice the draft.
• Cracked or chalking exterior frame surfaces. On Therma-Tru’s earlier vinyl formulations, prolonged UV exposure causes the capstock to embrittle. The frame is structurally compromised and will crack under wind load; replacement is the only sound option.

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Replacement Cost & What’s Included

Every quote is itemized: part number, labor line, and disposal. The price we write is the price on the invoice - Haven Clause 1, no exceptions. Our 365-Day Done Right Promise covers the installation and the part; if the balance creeps or the IGU fogs inside a year, we replace it and document the fix in your photo record.

DIY or Call Us?

There is safe checking, and there is work that belongs to a technician with the correct tools.

You can safely verify the model: open the sash and photograph the label sticker on the frame header or the etched code in the glass corner. You can check the balance stamp by tilting the sash inward (on tilt-wash units) and reading the number on the balance shoe. What you should not do is remove a fixed sash or attempt to reglaze an IGU - the spring tension in a constant-force balance can release suddenly, and broken glass edges are sharper than they look. We have replaced balances where the homeowner’s screwdriver slipped and punctured the jamb liner, converting a $310 job into a $670 frame repair. Measure once, quote it straight, install it right - that’s the whole business.

Call (772) 362-5402 and we will schedule a measured survey. You keep the document; we keep our copy. The quote matches it exactly.

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