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.
Gelco Damper Repair: The Dallas Owner’s Guide
A Gelco damper repair in Dallas typically runs $285 to $540 installed, depending on whether we’re replacing the cable assembly, the damper plate, or the entire top-sealing unit. We keep the most common Gelco replacement parts on the truck, so most repairs happen in a single visit. The way most Dallas homeowners discover the damper has failed is a draft they can’t explain in July, or a gas bill that climbs every December while the fireplace sits unused.
The Gelco damper is a top-sealing unit, which means it lives at the very top of the flue instead of the throat of the firebox like older cast-iron dampers. It closes against a rubber gasket to seal the flue when the fireplace isn’t burning. When that gasket rots or the cable snaps, you get a chimney that breathes outside air straight into your living room all year long. We see it all the time in older Dallas homes, especially the brick ranches in Lakewood and East Dallas where fireplaces haven’t been touched since wall-to-wall carpet was in style.
Key Takeaways
- Parts are Gelco-specific; the cable length and plate diameter have to match your flue size exactly.
- A failing top-sealing damper lets conditioned air escape year-round, not just during fireplace season.
- We give you a written price before any work starts, and the repair carries the 365-Day Done Right Promise in writing.
Which Gelco Models This Applies To
Gelco top-sealing dampers come in a few families: the hinged plate (“LYRE” style), the round flat-plate (“LD” and “TD” series), and the multi-flue rectangular versions. Most single-flue Dallas fireplaces use the round flat-plate design in either 8-inch or 9-inch diameter, but we’ve pulled 13-inch units out of some of the bigger masonry chimneys in Preston Hollow. The thing nobody tells you? The cable housing length is the gotcha. A 9-inch plate bought online will not work if the cable housing is 30 inches and your flue is 28. You’d think “close enough” works – it doesn’t. The cable will bind, the plate won’t seat, and you’ll be back on the phone with us anyway.
A quick way to identify your model: look up from the firebox with a flashlight. If you see a braided stainless cable running up the flue, that’s the operating cable. If the plate has a visible hinge on one side, it’s the hinged style. The flat-plate models center the cable and sit level. For OEM vs. aftermarket: Gelco-branded replacement plates use a specific heat-cured silicone rubber gasket material (rated 500°F); aftermarket options from other brands often use a thinner, softer rubber that fails in three to five years. We can install either, but we’ll show you the price side by side and recommend the one we’d put in our own house. For most customers, the OEM part is the better dollar-per-year value.
One honest note: Ashby Chimney Dallas is an independent service provider. We install and repair Gelco dampers, and we stock their replacement parts, but we’re not affiliated with Gelco. When you call us, you get us – not a manufacturer’s call center.
Styles & brands we work with





Signs Your Gelco Damper Repair Is Failing
- The T-handle or lever pulls hard and then goes slack. That’s the cable separating inside the housing. The steel strands fatigue one at a time until the whole assembly lets go. It won’t fix itself, and forcing the handle usually ruins the cable housing too.
- You hear a metal-on-metal scrape when operating the damper. The plate is dragging on the inside of the flue liner because the centering springs have worn out. In clay tile liners, that scraping eventually chips the tile edge, which means a bigger bill later.
- Downstairs smells like last winter’s fires in August. If the damper isn’t sealing, warm Dallas air rises out of your air-conditioned house through the flue and pulls sooty odor right back down into the room. This is the number one Gelco failure we fix in the summer.
- There’s daylight visible around the plate when it’s closed. Stand in the firebox and look up with a flashlight. A good seal means zero light around the gasket edge. Any gap at all is air you’re paying to cool or heat.
- You can open the damper, but you can’t lock it closed. The latch mechanism at the bracket has worn or the gasket has compressed unevenly. When the lock doesn’t catch, the plate hangs a fraction of an inch open and your utility bill feels it every month.
Replacement Cost & What’s Included
What you’ll pay in Dallas breaks down like this:
| Service | Typical Installed Price |
|---|---|
| Gelco gasket replacement only | $185 – $240 |
| Cable assembly replacement | $220 – $310 |
| Complete top-sealing damper replacement (standard single flue) | $385 – $540 |
| Complete replacement (multi-flue or oversized) | $520 – $680 |
The spread depends on three things: how easy the flue is to access from the roof or firebox, what model and size we’re matching, and whether the old bracket comes out cleanly or needs a mason’s touch. Every quote includes the parts, labor, cleanup, camera inspection to confirm the seal, and a photo report of the finished job. Our written price is the price – no surprise add-ons when we’re on the roof. Since 2002, anyone who’s used Ashby knows the number on the invoice matches the number we quoted at the door.
See the difference
Before
After
Before
After
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AfterDIY or Call Us?
You can safely check a few things yourself: the T-handle’s mounting screws, whether the cable path is obstructed, and what the plate looks like from inside the firebox with a flashlight. None of that requires tools or a ladder. What you shouldn’t do is pull a failed cable, loosen the bracket, or try to replace a top-plate from a ladder on a two-story Dallas roof. Top-sealing damper work means working at height above an open flue, and if you drop a wrench or a plate down a clay tile liner, the repair cost multiplies quickly. Nathan Corliss, owner here at Ashby Chimney Dallas, started learning this trade at Los Angeles Trade-Technical College before spending more than a decade running crews across the Dallas area. He’s been on enough Lakewood roofs to know which ones have chimney access that’ll make you rethink DIY. If your Gelco damper is giving you trouble, call us at (361) 314-3193. We answer the phone live, 24/7, and we’ll tell you straight whether it’s a repair or a replacement before we ever set a ladder against the house.
FAQs
A gelco top-sealing damper in Dallas typically lasts 10 to 18 years, depending on how often the fireplace is used and whether it’s a wood-burning or gas log setup. The rubber gasket is usually the first thing to fail, around the 8- to 12-year mark for most Dallas homeowners we serve. When the gasket goes, you’re losing conditioned air every hour of the year – not just in the winter.
A Gelco damper can often be repaired with a simple cable or gasket replacement, but there is a line where repair stops making sense. If the plate is warped, cracked, or badly scored, the best move is a full replacement. We’ll show you the condition on camera at the time of service and give you the price for both options before you decide. Call (361) 314-3193 with your model info and we’ll give you a straight answer on the phone.
A standard Gelco damper replacement usually takes 60 to 90 minutes, including the roof access, firebox work, camera check, and cleanup. Multi-flue or oversized jobs can run up to two hours. We schedule the work at a time you can be home, and we show up when we said we would.
We stock the most common Gelco gaskets, cables, and complete replacement units in our Dallas service vehicles, so there’s no shipping delay on most repairs. If you have an unusual flue size, we can usually source the exact part within a few days. The brands we keep alongside Gelco are DuraFlex and HeatShield, which covers most liner and repair situations around here.
Call for a Straight Answer
If your Gelco damper has been acting up, don’t guess at it. We’ll tell you the price first and put it in writing before we touch anything. “Tell you the price first, do the work right, put it in writing – that’s the whole job.” That’s the Kingswell Way, and it’s how every Ashby Chimney Dallas job has run since 2002. Call (361) 314-3193 for a free estimate – no pressure, no games, just a straight answer about your chimney.
Written by Nathan Corliss, Owner, Ashby Chimney Dallas at Ashby Chimney Dallas, serving Dallas and nearby areas.