Level 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 Plano Owner’s Guide
Gelco damper repair in Plano typically runs $340-$620 installed, depending on whether the throat plate, frame, or entire assembly needs replacement. We stock Gelco-compatible parts on our trucks and can usually complete the repair in a single visit. Most Plano homeowners discover the problem when they feel a cold downdraft or smell smoke backing into the living room on the first fire of the season.
Corrine Halstead and our crew have replaced Gelco dampers in homes from Willow Bend to Legacy West, and the pattern is consistent: these units fail gradually, then suddenly. The cast-aluminum throat plate warps from years of Plano’s freeze-thaw cycles, or the cotter-pin hinge seizes with rust from summer humidity. The camera doesn’t guess. Neither do we. A Level 2 inspection with a flue camera confirms exactly what’s broken before we quote anything in writing.
Which Gelco Models This Applies To
Gelco manufactured throat dampers under several product lines, and the repair approach depends on which generation is installed. The most common in Plano homes built between 1985 and 2010 are the Gelco cast-aluminum top-sealing dampers (model prefixes GCS and GCD) and the older cast-iron throat assemblies (series 100 and 200). The GCS-8 and GCD-10 are nearly identical from below, but the GCD-10 uses a wider 13.5-inch frame that won’t retrofit into a standard 12-inch lintel opening without masonry modification.
We source replacement parts through Haven’s buying network, which includes both OEM Gelco components and aftermarket equivalents from Famco and Copperfield. For most Plano jobs, we install a stainless-steel aftermarket throat plate with a silicone seal, rated to 1,200°F, which outlasts the original cast-aluminum design in North Texas conditions. The OEM Gelco part runs 15-20% higher and carries the same functional warranty. We mark the exact model number, frame width, and hinge orientation on your written quote before ordering anything.
Signs Your Gelco Damper Repair Is Failing

- Cold air pours down the flue even when the damper is “closed.” The cast-aluminum throat plate has warped or the silicone seal has hardened, leaving a gap that lets conditioned air escape upward and winter drafts blow downward. We measure the gap with a feeler gauge during camera inspection; anything over 3/16 inch costs you money on your heating bill.
- The damper handle moves but the plate doesn’t open or close fully. The cotter-pin hinge has corroded, or the linkage rod has slipped its connector. In older Gelco 100-series units, the rod is a single piece of mild steel that rusts solid where it passes through the smoke shelf.
- You smell smoke or hear whistling during a fire. A partially open damper creates turbulent draft, pulling smoke into the room instead of up the flue. In Plano’s newer tight-construction homes near Russell Creek, negative pressure from HVAC systems makes this worse.
- The handle is stuck completely and won’t budge. The frame has shifted in the lintel, binding the plate, or creosote buildup has cemented the hinge. We see this in homes that burn pine or unseasoned oak, common in Collin County.
- Rust flakes or black debris fall onto the firebox floor. The cast-iron frame is spalling, or the steel linkage is disintegrating. This debris is a sign the assembly is past preventive repair and needs full replacement before the frame cracks.
Before
AfterReplacement Cost & What’s Included
| Component | Price Range (Plano) |
|---|---|
| Gelco-compatible throat plate replacement | $340-$480 |
| Full damper assembly (frame + plate + hardware) | $480-$620 |
| Masonry modification for oversized frame | $180-$290 additional |
Every repair includes NFPA 211 Level 2 camera inspection of the flue, written scope and price before work starts, removal and disposal of the failed component, installation of the new assembly with stainless fasteners, operational test, and a documented photo record uploaded to your job file under Haven Standard Clause 4. The 365-Day Done Right Promise covers labor and materials. If we open the flue and find the smoke chamber or liner also needs attention, we show you the camera footage and write a separate scope - no bundled pressure, no surprise additions.
DIY or Call Us?

There’s a safe middle ground here. You can verify the model number from the stamped label on the frame edge, measure the throat opening width and depth, and check whether the handle linkage moves freely from below. What you should not do is climb into the firebox or reach up past the lintel to manipulate a seized plate. The assembly is heavy cast metal, positioned directly above your face, and a slipped wrench can crack the firebrick or dislodge the frame into the flue.
We’ve been called to Plano homes where a homeowner’s attempted repair dropped the throat plate down the flue, requiring a full chimney sweep and camera retrieval. The correct tool for this job is a damper hook set with a flashlight and a second set of eyes - that’s what our technicians bring. If you want to confirm the symptoms yourself, fine. For the actual swap, call (469) 240-3101 and we’ll quote it in writing before we dispatch.
FAQs
A cast-aluminum Gelco throat damper typically lasts 15-25 years in North Texas, though we’ve seen them fail at 12 in homes near White Rock Creek with heavy humidity and frequent freeze-thaw. Stainless-steel replacement plates we install are rated for 30+ years. Call (469) 240-3101 for an exact quote - estimates are free.
Sometimes. A seized linkage can be freed and re-greased, and a minor warp can be shimmed if the gap is under 1/8 inch. But once the cast aluminum cracks or the frame rusts through, repair is temporary at best and unsafe at worst. We show you the camera footage and give an honest call. Call (469) 240-3101 for an exact quote - estimates are free.
Most Gelco damper replacements take 90 minutes to 2 hours from ladder set to final test, assuming standard access and no masonry modification. We book a half-day window and usually finish well under. Call (469) 240-3101 for an exact quote - estimates are free.
We carry throat plates and full assemblies for the GCS, GCD, and series 100/200 lines on every Plano service vehicle. Odd sizes or the rare 15-inch commercial frame ship overnight from our Dallas warehouse. We confirm fit before we leave the shop. Call (469) 240-3101 for an exact quote - estimates are free.
Emberly Chimney Cleaners Plano is an independent service provider and is not affiliated with Gelco Manufacturing. We also stock compatible parts from DuraFlex and HeatShield.
Written by Corrine Halstead, Owner, Emberly Chimney Cleaners Plano at Emberly Chimney Cleaners Plano, serving Plano and nearby areas.





Before
After
Before
After