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.
HeatShield Damper Repair: The Denver Owner’s Guide
HeatShield damper repair in Denver typically runs $340-$620 installed, depending on whether the damper plate, frame, or both need replacement. We stock HeatShield-compatible damper hardware on every truck and can usually match your model series same-day. Most Denver homeowners discover the failure on the first cold morning in October or November, when they open the damper and it hangs crooked, won’t seal, or drops a rust flake into the firebox.
Which HeatShield Models This Applies To
HeatShield damper assemblies fall into two main lines: the original cast-iron throat dampers (marked HS-TD on the frame stamp) and the later stainless pivot-plate models (HS-SP series, introduced around 2016). The cast-iron units are common in Denver homes built between 2005 and 2015, especially in the stapled-up developments around Stapleton and Green Valley Ranch where HeatShield liners were heavily spec’d. The stainless pivot-plate models run lighter and handle Colorado’s wide temperature swings better, but the pivot pin and spring-tension keeper are the failure points we see most.
To identify yours, look up the firebox throat for a stamped metal tag or etched code on the damper frame’s right-hand side. If the tag’s worn off, measure the throat opening width and depth, plus the damper plate thickness. The HS-TD plates run 5/16-inch thick; the HS-SP plates are 3/16-inch with a beveled leading edge. We carry both OEM HeatShield hardware and aftermarket equivalents from Gelco and Famco through our Haven buying network. For most Denver replacements, the aftermarket pivot-plate assembly matches spec at a lower parts cost, but we always show you both options in writing before ordering.
Signs Your HeatShield Damper Repair Is Failing

- The handle turns but the plate doesn’t move. The linkage rod or cotter pin has corroded through, common in Denver homes where the chimney crown cracked early and moisture dripped down the flue for seasons before anyone noticed. The plate itself may be fine, but the connection is lost.
- You feel a cold draft even with the damper “closed.” The plate has warped or the frame seat has eroded from acidic condensation, especially in high-efficiency gas setups that run cooler flue temps. A dollar-bill test at the throat confirms it: if you can slide a bill through, you’re heating the neighborhood.
- The plate drops or tilts when opened. The pivot pin has wallowed out its bushing, or the spring keeper on HS-SP models has lost tension. This one gets worse fast, and a dropped plate can block the flue partially open, which is a carbon monoxide risk.
- Rust particles or scale in the firebox. Denver’s freeze-thaw cycles accelerate corrosion on cast-iron plates that sit in a cold flue all summer. The rust isn’t cosmetic; it means the plate thickness is degrading and the seal surface is pitted.
- Squealing or grinding when you operate the handle. The linkage is binding, usually from creosote buildup at the throat combined with a dry pivot. In Denver’s dry climate, homeowners often skip annual sweeps, and Class III creosote, the hardened, tar-like stage, seizes the mechanism.
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AfterReplacement Cost & What’s Included
| Service | Price Range |
|---|---|
| HS-SP pivot-plate assembly (aftermarket), installed | $340-$460 |
| HS-TD cast-iron damper plate and frame, installed | $480-$620 |
| Linkage rod and handle kit only | $180-$260 |
| NFPA 211 Level 2 camera inspection with photo record | Included |
What drives the range: throat accessibility (some Denver fireplaces have tight smoke chambers that need extra time), whether the frame seat needs resurfacing, and whether we find secondary issues like a cracked smoke shelf. We deliver a written price before any work starts, Clause 1 of the Haven Standard, with the scope and warranty spelled out. Every damper repair includes our 365-Day Done Right Promise. Materials come through our Haven buying network from HeatShield, Gelco, Famco, and other suppliers, procured to keep customer prices honest.
DIY or Call Us?

There’s a safe line here, and it’s lower than most homeowners think. You can check the handle operation, shine a flashlight up the throat to spot obvious rust or tilt, and confirm whether the plate moves with the handle. That’s it. What you cannot safely do: reach past the throat into the flue to free a stuck plate, remove a tensioned pivot spring on HS-SP models, or reseat a cast-iron plate that weighs 15-20 pounds while working overhead in a confined firebox. The spring on the HS-SP keeper is under enough load to snap a finger, and a dropped cast-iron plate will crack a firebrick or your wrist. We’re licensed and insured, our technicians are background-checked and uniformed, and you’ll get a text when your tech is en route with a name and photo. Call (720) 674-7312 for a written estimate, no charge.
FAQs
In Denver’s climate, a cast-iron HeatShield damper typically lasts 12-18 years if the chimney crown stays intact and annual sweeps keep creosote off the mechanism. Stainless pivot-plate models run 15-25 years, though the spring keeper may need replacement at year 10. The freeze-thaw cycling and dry winters here are harder on cast iron than on the coasts. Call (720) 674-7312 for an exact quote on your model, estimates are free.
Sometimes. A detached linkage rod, a missing cotter pin, or a handle replacement is a straightforward repair. But if the plate is warped, the frame seat is eroded, or the pivot bushing is wallowed out, replacement is the only fix that seals properly. We won’t know which category you’re in until we get a camera down the flue. Call (720) 674-7312 for an exact quote, estimates are free.
Most HeatShield damper replacements take 90 minutes to two hours from ladder set to final test burn. Tight smoke chambers or a frame that needs resurfacing can push it to three hours. We bring the parts, the camera, and the documentation gear on every truck. Call (720) 674-7312 for an exact quote, estimates are free.
We stock HS-SP pivot-plate assemblies, HS-TD cast-iron plates, linkage kits, and handle hardware on every service truck. For less common sizes or older HS-TD frames discontinued before 2012, we can source through our Haven buying network with next-day delivery. Call (720) 674-7312 for an exact quote, estimates are free.
Level Two Chimney Denver is an independent service provider, not affiliated with HeatShield. We also stock and install damper hardware from DuraFlex and Gelco.
Corrine Halstead and her team have worked HeatShield systems from Capitol Hill to the brick Victorians along Federal Boulevard. The camera doesn’t guess. Neither do we. Every job gets the NFPA 211 Level 2 inspection, the photo record, and the written price before a tool comes out. That’s been Clause 4 of the Haven Standard since 2009.
Written by Corrine Halstead, Owner, Level Two Chimney Denver at Level Two Chimney Denver, serving Denver and nearby areas.





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