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Unilock Windows & Doors: The San Antonio Owner’s Guide
If you have a Unilock window or door with a failing hinge, lock set, roller, or weather seal, we stock and install Unilock-compatible replacement parts across San Antonio. Installed pricing for most window and door part replacements in San Antonio runs $180 to $850 depending on the part and accessibility, and we can usually match the part and get it installed within a few business days. The most common way owners discover a problem: a door starts dragging, a window won’t stay up, or a lock no longer throws cleanly, and suddenly a window that worked fine for a decade needs attention.
We’re an independent San Antonio service provider, not affiliated with Unilock, and that matters for one reason: we don’t push a single product line. We match the part that fits your existing unit, whether that’s an OEM Unilock component or a quality aftermarket equivalent that holds up better in South Texas heat. Isaac Pruett has been working San Antonio jobs long enough to know which parts fail first in this climate, and his crew keeps the most common Unilock hardware on the truck so a first visit usually turns into a completed repair.
Which Unilock Models This Applies To

Unilock’s window and door hardware lines span multiple series, and the part you need depends on the unit’s age, frame material, and where it was installed. Most San Antonio homes built or renovated in the last 15 to 20 years use Unilock’s casement, awning, sliding patio, and hinged entry door hardware. The quickest way to identify your part: look for a stamped code on the hinge leaf, the lock faceplate, or the edge of the sash. It’ll be a series letter or number, sometimes followed by a size designation like 4-1/2 or 5-1/8 for hinge screw spacing.
Here’s the compatibility gotcha every San Antonio homeowner should know: Unilock changed its roller and hinge geometry around 2016 on select patio door lines, and the older parts are no longer produced. If you have a pre-2016 sliding door, a direct OEM replacement may not exist. In those cases, we machine-match the roller profile to a current aftermarket equivalent that drops into the original track. That’s the difference between a $90 roller swap and a $3,000 door replacement. Bringing us the old part, or a clear photo with a tape measure beside it, saves a second trip.
Styles & brands we work with







Signs Your Unilock Windows & Doors Is Failing
- Door drags or skips on the track: This is almost always a worn roller bearing or a flattened roller wheel. Left alone, the door starts chewing into the track, and then you’re looking at threshold or full-track replacement, not just a roller.
- Window won’t stay open: On double-hung and single-hung Unilock windows, this points to a failed balance mechanism, either the spring or the block-and-tackle channel. The window still seals, but the hardware is doing none of the work.
- Lock throws hard or not at all: San Antonio’s clay soil shifts, and door frames move just enough to misalign the strike plate. Sometimes it’s the lock itself; more often it’s the alignment, and forcing it just breaks the latch teeth.
- Air leaks or visible daylight around the sash: Weatherstripping on Unilock windows is a foam or brush seal that flattens permanently after years of sun exposure. Once it hardens, the sash loses its compression seal and your AC bill feels it.
- Handle spins or feels loose on a casement or awning window: The crank mechanism’s gear teeth are stripping. In San Antonio’s heat, the internal grease dries out, and the plastic gears inside the operator fail faster than they do in milder climates.
See the difference
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After
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AfterReplacement Cost & What’s Included

For Unilock windows and doors, part-specific replacement in San Antonio typically falls into these ranges:
- Sliding door roller replacement: $180 – $360 per door, including both rollers and track cleaning
- Window balance replacement: $120 – $280 per window
- Casement or awning crank operator: $200 – $450 installed
- Door lock set or mortise lock replacement: $150 – $400 including hardware
- Weatherstripping replacement (per window or door): $90 – $220 including material
- Full window replacement (Unilock-compatible, per window): $450 – $1,500 depending on size, glass, and frame condition
Every quote includes the part, labor, trip, and clean-up in one written price before we start, which is the only way we work. No surprise line items after the fact. The work itself is covered under our 365-Day Done Right Promise: if the repair fails within a year of completion, we return and make it right at no cost to you. That’s a written guarantee with stated terms, not a handshake.
DIY or Call Us?
Some things you can safely check yourself: whether the screws on the hinges and lock faceplate are tight, whether the track is clean and free of dirt and pet hair, whether the weatherstripping is visibly cracked or flattened. Those are five-minute inspections that cost nothing and often explain the symptom.
What you should not do is disassemble a window balance or remove a patio door from its track. The balance spring on a double-hung Unilock window is under constant tension, and when it releases, it releases fast. Patio doors are heavy, awkward, and easy to drop through glass or onto a hand. Same goes for mortise locks with internal gears, once they’re opened, the clockwork inside rarely goes back together without a proper parts diagram. A wrong turn on a balance spring has put more than one San Antonio homeowner in urgent care. If the part involves tension, weight, or interior clockwork, call us at (254) 269-5071 and we’ll send someone who does this every week.
FAQs

Plan on 15 to 25 years for the window or door unit itself, but expect hardware components like rollers, balances, and weatherstripping to need replacement every 5 to 10 years in San Antonio’s heat and UV exposure. The frame usually outlasts the parts, which is why part replacement is almost always the smarter money compared to a full unit swap. Call (254) 269-5071 for an exact quote on your specific issue.
In most cases, no, and here’s why: the parts that fail are wear items with moving components, sealed spring cartridges, or hardened seals that cannot be reconditioned. That said, some door alignment issues are repairable by adjusting the hinges or strike plate rather than replacing them. We’ll tell you if a repair makes sense, and if it doesn’t, we won’t sell one. Estimates are free.
Most Unilock part replacements take 45 minutes to two hours on site, depending on the part and access. A sliding door roller replacement on the ground floor is usually under an hour. A second-story window balance with a tight ladder approach adds time. We’ll give you a realistic time window when you schedule, not a vague “we’ll be there sometime.”
We keep the most common Unilock hardware on our trucks: patio door rollers, casement operators, double-hung balances, strike plates, and weatherstripping in standard profiles. Obscure or discontinued parts may take a few days to source, and we’ll tell you that upfront. If we need to order, we give you the written price before the part is ordered, so you know the total cost before you commit to anything.
If you need a Unilock window or door part matched and installed in San Antonio, call (254) 269-5071. We’ll walk through what you’re seeing, give you a straight price range over the phone, and schedule the visit when it works for you. Know who’s coming, know what it costs, know it’s covered, that’s the whole job before the job starts.
Written by Isaac Pruett, Owner, Mason Remodeling Co San Antonio at Mason Remodeling Co San Antonio, serving San Antonio and nearby areas.


