Masonry repair
Sweep & inspection
Caps & crowns
Flue relining
Gas fireplace serviceLevel 1 sweep and inspection to the NFPA 211 annual standard - flue, crown, cap, and flashing checked and photographed
Chimney sweep logs do not sweep chimneys. They loosen some creosote - which then falls where a brush and vacuum still have to collect it.
HeatShield Damper Repair: The San Antonio Owner’s Guide
HeatShield damper repair in San Antonio typically runs $340 to $680 installed, depending on the model and whether the damper plate, cable assembly, or mounting frame needs replacement. We stock common HeatShield damper components on the truck and can usually complete the swap in one visit. Most homeowners discover the damper failed because the fireplace suddenly drafts cold air into the living room in January, or the handle spins freely without engaging anything. If the damper won’t hold its position, you’re looking at a worn cable, a warped plate, or a broken hinge pin, and those are all fixable.
Which HeatShield Models This Applies To
HeatShield has manufactured several damper series over the years, and the part compatibility is not as forgiving as some chimney products. The original HeatShield damper assemblies came in standard throat sizes of 8, 10, and 13 inches, but the second-generation units moved to a different cable routing that makes first-gen cables incompatible. If your damper frame has a small metal tag riveted to the front lip, that’s your model reference. No tag? Measure the throat width side to side, and look at the cable exit point. Cables that exit through the smoke shelf use the older spec; cables that route through a side channel use the newer assembly. This matters because HeatShield no longer manufactures the original series, and quality aftermarket equivalents are the practical path for those units. Alcott Chimney San Antonio is an independent service provider, not affiliated with HeatShield. We install both OEM parts when available and aftermarket damper components we’ve vetted against the original specs, made from cast iron and stainless steel cable rather than the aluminum you see in generic box-store replacements. In San Antonio’s damp spring air, aluminum cable housings corrode and seize up faster than you’d expect.
Styles & brands we work with





Signs Your HeatShield Damper Repair Is Failing
- The handle spins without resistance. The cable has either snapped at the connector or slipped off the damper plate. When this happens, the damper usually sits half-closed, letting conditioned air escape while leaving just enough of a gap for birds or wasps to inspect your flue.
- The damper won’t stay open or closed. HeatShield dampers use a spring-loaded detent to hold position. When that spring fatigues, the plate drifts. You’ll notice the fireplace drafting smoke into the room on windy days.
- A metallic rattle from the throat area. That’s usually the damper plate vibrating against the frame because a hinge pin wore down or the frame warped from repeated heat cycling.
- Visible rust or flaking on the plate edges. San Antonio humidity accelerates rust on exposed damper steel. A rusted plate warps, and a warped plate never seals fully, even after you replace the cable.
- Cold air streaming from the fireplace during winter. A HeatShield damper with a compromised gasket or a warped plate leaks indoor air 24 hours a day. Your heating bill will tell you before your eyes do.
See the difference
Before
After
Before
After
Before
AfterReplacement Cost & What’s Included
For San Antonio homeowners, expect the following installed ranges:
- Damper cable replacement: $180 to $260
- Damper plate replacement (HeatShield-compatible): $320 to $480
- Full damper assembly replacement (frame, plate, cable, hardware): $450 to $680
The range depends on throat size, whether the original mounting frame is salvageable, and how much debris needs to be cleared from the smoke shelf before we can work. Every HeatShield damper repair we quote includes the part, labor, removal of the failed component, and a written price before any work starts, so there’s never a surprise charge at the end. Ruben Castellano and our crew also clean the mounting surface and test the damper through ten full open-close cycles before we pack up. The work carries our 365-Day Done Right Promise: if the damper fails within a year, the second visit is free.
DIY or Call Us?
You can safely measure the throat opening, check for a model tag, and photograph the cable routing before calling. That information helps us bring the right part. What you should not attempt is removing the damper plate yourself. HeatShield damper frames are fastened under spring tension in several series, and a released plate drops hard enough to break fingers. The cable also routes through the smoke shelf, which means reaching it properly requires working from inside the firebox with the right angle. That’s not a ladder-and-flashlight job. If the damper is stuck, jammed, or the cable is visible but won’t move, call (903) 515-5079. We’ll tell you over the phone whether it sounds like a cable or a plate, and we’ll give you a straight price range before we schedule anything.
FAQs
A properly installed HeatShield damper should last 12 to 18 years in San Antonio before the cable or hinge components need attention. Humidity and frequent use shorten that range; fireplaces used less than a dozen times a year often see damper problems earlier because the plate sits in damp air for months without heat to burn off moisture. We regularly replace dampers that are structurally fine but have seized cables from corrosion, especially in older homes near the Olmos Basin where humidity lingers.
It depends on what failed. Cables, hinge pins, and detent springs are straightforward repairs. A cracked or severely warped plate needs replacement because no adjustment will make it seal properly. We’ll show you the damaged part before we recommend anything, and if the plate is merely misaligned, we’ll say so. No one should sell you a full assembly when a $12 spring fixes the problem.
Most damper replacements take 60 to 90 minutes from setup to cleanup. Full assembly swaps, where the original frame is corroded or the throat needs cleaning first, can run up to two hours. We carry common HeatShield cable lengths and plate sizes on the truck so the work happens in one visit.
Yes. We stock HeatShield-compatible damper plates in 8, 10, and 13 inch throat sizes, replacement cable assemblies for both first and second generation models, hinge pins, and detent springs. We also stock parts for DuraFlex and Gelco systems, so if the damper job reveals an adjacent issue with the liner or cap, we can address it the same day.
Ready for a fixed price on HeatShield damper repair in San Antonio? Call (903) 515-5079 and you’ll get a live person, not a voicemail. We’ll walk through what you’re seeing, quote a straight range, and send a technician you already know by name and photo before we ever ring your bell. Written price before work starts. Written guarantee on the repair. That’s how we’ve done it since 2002.
Written by Ruben Castellano, Owner, Alcott Chimney San Antonio at Alcott Chimney San Antonio, serving San Antonio and nearby areas.