Gelco Damper Repair Nationwide

Gelco Damper Repair: The San Antonio Owner’s Guide

We stock and install Gelco-compatible damper repair parts across San Antonio, with most complete damper replacements running between $385 and $720 installed, depending on the throat size and whether the old frame can be reused or needs to be cut out. Most Gelco damper jobs in San Antonio are completed in a single visit since we keep the common Lyemance and top-sealing damper parts on the truck. You usually discover the problem the first cold evening of October: you open the damper, light the fire, and within ten minutes smoke rolls back into the living room instead of rising up the flue.

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The damper is the movable metal plate that seals your fireplace throat when the fire is out and swings or cranks open when you want to burn. When it fails, the fireplace becomes a drafty hole in your house in winter and a highway for attic air in August. Danny Cortes has walked hundreds of San Antonio homeowners through this exact diagnosis, often sketching the failed hinge or warped plate in his notebook so they can see it before any work begins.

Which Gelco Models This Applies To

Gelco dampers fall into two broad groups: the older throat-mounted cast iron dampers built into masonry fireplaces, and the newer Lyemance-style top-sealing dampers that mount at the flue crown. The repair approach changes completely depending on which one you have. Throat dampers usually fail at the hinge pin or the lever mechanism, while top-sealing dampers fail at the cable, the spring, or the rubber silicone gasket that degrades under Texas sun.

Here’s the compatibility gotcha that catches San Antonio homeowners off guard: Gelco throat dampers were manufactured in set size ranges (typically 24″, 30″, 36″, and 42″ widths), and a damper that measures 28-3/8″ across the throat will not accept a 30″ replacement plate without grinding the firebox or fabricating a custom frame. We measure the actual throat opening to the nearest eighth of an inch before quoting, never by eye. When an original Gelco part is no longer manufactured in your exact size, we install a quality aftermarket equivalent from Lyemance or Copperfield, cut to fit your opening. These are often as good as or better than the OEM part, with the same warranty coverage.

Signs Your Gelco Damper Repair Is Failing

• Smoke rolls into the room on startup. The damper plate is stuck partially closed, usually from a bent hinge or a lever that’s jumped its track. This is the most common call we get in San Antonio between November and February.
• The handle spins freely with no resistance. The cotter pin connecting the lever arm to the damper plate has sheared or fallen out. The plate is now sitting closed, and no amount of cranking will open it.
• You feel a cold draft even with the damper “closed.” The plate has warped from years of heat cycling, or the frame has shifted slightly. The damper now closes against nothing, leaving a gap the width of a pencil around the edges.
• You hear a rattling or scraping when you operate the handle. The pivot hardware has worn oval, so the plate is dragging against the firebox walls. Left alone, this gets worse and eventually snaps the hinge entirely.
• Water staining inside the firebox, but only in summer. A failed top-sealing Gelco damper lets rain straight down the flue. The rubber gasket has cracked from UV exposure or the spring has lost tension, and the plate no longer seals against the crown.

Replacement Cost & What’s Included

For San Antonio homes, a complete Gelco damper replacement typically runs $385 to $720 installed. A repair of the existing damper, meaning a new hinge pin, replacement lever, or cable adjustment, runs closer to $165 to $285. The price spread comes down to three things: whether the old damper frame is salvageable, whether we’re working at the firebox throat or up on the roof for a top-sealing unit, and the width of the opening.

Every quote includes the part, the labor, removal of the failed component, and a photo of the completed work before we pack up. DuraFlex and HeatShield parts come into play on the same job when the damper failure has also damaged the flue liner, but we’ll show you camera footage of that before recommending anything, and we’ll tell you plainly if the liner can wait. Your written price comes before any work starts, always, and the whole job is covered by our 365-Day Done Right Promise. If it’s not right, we make it right.

DIY or Call Us?

You can safely do one thing: inspect. Open the damper fully with a flashlight and look at the hinge pins, the lever connection, and the plate edges. If you see an obvious broken cotter pin, that’s a real finding and worth photographing for reference. What you should not do is go at a cast iron damper plate with a pry bar. These plates are heavy, the hinge hardware is under load in certain positions, and a plate that slips while you’re working inside the firebox sends cast iron into your hands or worse. We have seen homeowners crack firebrick and bend damper frames trying to free a stuck plate, which turns a $200 repair into an $800 replacement.

Top-sealing dampers add another layer: you’d be working at the flue crown, which means getting on the roof with tools and sealant. Let us handle that. Danny and our crew do this every week across San Antonio, from Alamo Heights to the neighborhoods near the Pearl, and we’d rather show you the failed part and the fix than clean up after a DIY attempt gone sideways. Call (361) 491-3153 and we’ll schedule a time that works for your family, kids and pets included.

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