Gelco Flue Liner Replacement Nationwide

Gelco Flue Liner Replacement: The Denver Owner’s Guide

We stock and install Gelco-compatible flue liner replacement in Denver, with typical installed pricing running $2,800-$5,400 depending on height, diameter, and whether your existing tee and top plate can be reused. Most Gelco liner swaps we book in Capitol Hill, Highlands, and Wash Park are completed in a single day once the written scope is approved. Homeowners usually discover the failure during a sweep when the camera shows gaps, corrosion scaling, or orange peel pitting in the stainless wall, or when they spot water staining on the firebox after a spring snow followed by a rapid Denver thaw.

Call (720) 674-7312

Which Gelco Models This Applies To

Gelco’s flue liner program breaks into two main series: the older Gelco-Pro round flexible liners (common in 1980s-2000s Denver builds, especially in Park Hill and Congress Park brick Victorians) and the current Gelco UL-listed 316Ti stainless line with the ribbed-wall design. The Pro series used a .005-inch wall thickness and a distinct crimped collar at the tee; current 316Ti runs .006-inch minimum with a welded seam and a different top plate bolt pattern. We source both OEM Gelco and compatible aftermarket equivalents through our Haven buying network, and the choice depends on what your existing top termination and tee look like. If your label is readable, the part number prefix tells the story: GPRO- for the legacy line, G316- for current production. When the label’s burned off, we measure inner diameter to the nearest eighth-inch and check wall rigidity with a bend test. Mixing a Pro-series tee with a 316Ti liner body will leak at the collar; we’ve caught that mismatch three times in Berkeley bungalows this past year alone.

Signs Your Gelco Flue Liner Replacement Is Failing

• Orange peel pitting on the camera scan. This is localized corrosion from acidic condensation, common in Denver’s dry climate where rapid temperature swings stress the stainless. The pits don’t seal, and each one is a starting point for a through-wall breach.
• White or green scaling at joints. Salt deposits mean flue gases are escaping at a tee or seam, usually because the original Pro-series crimp has worked loose after 15-20 years of expansion cycling.
• Water staining below the damper after spring snow. A compromised liner allows melt to track down the flue wall instead of shedding at the crown. In Denver’s March-April freeze-thaw cycles, this accelerates rust at the smoke shelf.
• Smoke smell in upper rooms during wind. A perforated liner near the top lets exhaust pressurize the chase cavity; older Stapleton and Lowry rebuilds with stucco chases show this pattern when the Gelco top plate gasket has hardened.
• Your sweep flags “liner movement” on the report. If the liner has dropped from its original top support, the bottom tee may no longer seat in the thimble, creating a direct path for CO into the basement.

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After

Replacement Cost & What’s Included

The spread comes down to three things: chimney height (a three-story Baker or Sunnyside row house adds 8-10 feet over a ranch), whether we can salvage your Gelco tee and top plate, and if the smoke chamber needs parge coating to restore proper draft geometry. Every quote is itemized in writing before work starts, per Haven Standard Clause 1. The liner itself carries a lifetime warranty; our labor is covered by the 365-Day Done Right Promise. Materials come through our Haven buying network from Gelco, DuraFlex, HeatShield, and Olympia Chimney, procured specifically to keep customer prices honest.

DIY or Call Us?

You can safely verify your Gelco model number from the attic or roof if you’re comfortable on a ladder and the pitch is walkable. Check the top plate label and snap a photo of any part stamping. Do not attempt to pull the liner yourself. Gelco flexible liners are tension-set at the top support; releasing that without proper anchoring can drop the entire run into the firebox, and the stainless edge is sharp enough to open a hand to the bone. More critically, a liner pulled without CO monitoring and proper chase sealing can leave exhaust leaking into wall cavities overnight. We pull, inspect, and replace with the camera running the full length both directions. The camera doesn’t guess. Neither do we. Call (720) 674-7312 when you’re ready for the written scope.

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