Therma-Tru Windows & Doors Nationwide

Therma-Tru Windows & Doors: The Sunnyvale Owner’s Guide

Therma-Tru windows and doors in Sunnyvale typically run $4,500-$15,000 for full replacement depending on series, opening count, and whether the home needs retrofitted flashing for older stucco exteriors common in the Birdland and Lakewood Village neighborhoods. We stock Therma-Tru-compatible sills, jamb liners, weatherstrip kits, and multipoint locking hardware for same-day repair on most Classic-Craft, Fiber-Classic, and Smooth-Star series units. Most Sunnyvale homeowners discover a problem when the multipoint lock won’t engage evenly, the door drags on the threshold after winter rains swell the jamb, or they feel a draft along the bottom rail that the weatherstrip no longer seals.

Call (650) 405-3637

Which Therma-Tru Models This Applies To

Therma-Tru organizes its entry systems by door slab material, and the parts differ significantly between lines. Classic-Craft uses a high-density polyurethane core with oak or mahogany grain; Fiber-Classic is fiberglass with a wood-grain surface; Smooth-Star is fiberglass with a smooth paint-ready skin. Each takes a different jamb width, hinge mortise pattern, and multipoint lock prep. The label is inside the hinge edge of the door slab, stamped with a six-digit model prefix and manufacture date. We match parts to that prefix, not to the homeowner’s visual description, because Therma-Tru revised its multipoint lock geometry in 2014 and again in 2019. The newer AVANTGUARD locks are not backward-compatible with the older MasterLock systems without replacing the full mortise pocket.

We source OEM Therma-Tru parts through authorized distribution, but for certain high-wear items we also stock quality aftermarket equivalents. The aftermarket adjustable sill caps and compression weatherstrip from Pemko and Reese fit precisely and carry comparable UV ratings, at roughly 30% less than factory-ordered components. For multipoint locks and hinge sets, we stay OEM. The labor to correct a misfit aftermarket lockset exceeds any parts savings.

Signs Your Therma-Tru Windows & Doors Is Failing

• Door slab drags or sticks in the frame. This usually means the composite sill cap has compressed or cracked, dropping the door’s bottom edge into the threshold. In Sunnyvale’s clay-heavy soils, minor foundation settlement accelerates this wear pattern.
• Visible daylight under the door when closed. The bulb-style weatherstrip along the bottom rail has lost its compression set. Therma-Tru’s Q-Lon foam weatherstrip degrades faster on south- and west-facing doors due to UV exposure and repeated thermal cycling.
• Multipoint lock deadbolt won’t extend fully. The lock faceplate or keepers have shifted, or the internal gearbox has worn. On pre-2014 units, the zinc alloy gearbox housing is prone to fatigue cracking after roughly 8,000 cycles.
• Condensation between glass panes on sidelights or doorlites. The insulated glass unit seal has failed. Therma-Tru’s standard IGU warranty is 20 years, but field failures in Sunnyvale often trace to installation without proper end-dam flashing, not manufacturing defect.
• Frame or brickmold shows soft spots or discoloration. Water intrusion at the sill pan or behind the jamb casing. Stucco-integrated installations without a proper sill pan and weep screed (the drainage channel at the base of stucco walls) trap moisture against the composite jamb.

Before

After

Replacement Cost & What’s Included

For Therma-Tru window and door work in Sunnyvale, our installed pricing follows the structure below. Every figure is a flat written price with scope detailed line by line before any work starts.

The range spreads based on three factors: whether the existing frame can be preserved or must be re-framed; stucco or siding repair scope after the opening is disturbed; and whether the home was built with 2×4 or 2×6 walls, which changes jamb width and trim complexity. Under Clause 1 of the Haven Standard, the written price includes all parts, labor, disposal, and a documented photo record of the completed work. Our 365-Day Done Right Promise covers the installation and hardware function. No change to scope proceeds without a signed change order.

DIY or Call Us?

A homeowner can safely inspect the door label, photograph any visible damage, and confirm the symptom against the list above. What we do not recommend: attempting to adjust or replace a multipoint lock, removing a prehung door from its frame, or cutting into stucco to investigate moisture damage. The lock components are spring-loaded and can release unexpectedly; door slabs on Therma-Tru units weigh 90-140 pounds depending on size and glass insert; and stucco penetration without proper weep screed restoration traps water against the framing. We carry the correct jamb spreaders, sill pan templates, and pneumatic staplers for weatherstrip seating on our trucks. Call (650) 405-3637 and we’ll schedule a free estimate with a written price before any work starts.

FAQs