Gelco Flue Liner Replacement Nationwide

Gelco Flue Liner Replacement: The San Antonio Owner’s Guide

Gelco flue liner replacement in San Antonio typically runs $1,800 to $3,400 installed, depending on the liner diameter, chimney height, and whether your existing Gelco components can be reused. We stock Gelco-compatible liner sections on our trucks and can usually complete the swap in a single visit once we’ve confirmed measurements. Most San Antonio homeowners discover their liner has failed during a routine sweep, when the camera shows cracks, gaps, or rust-through that wasn’t visible from the fireplace opening. Sometimes it’s a chimney fire that forces the issue. Either way, the fix is straightforward when you know exactly what you’re replacing and why.

Call (254) 276-4116

Key Takeaways:

• Gelco liners fail most often at the seams and the first 3 feet above the firebox, where heat stress is highest.
• We carry Gelco-compatible rigid and flexible liner sections, plus connectors, on the truck so most replacements don’t need a second trip.
• Every replacement includes a camera inspection before and after, a written price before work starts, and our 365-Day Done Right Promise in writing.
• Hadley Chimney San Antonio is an independent service provider. We’re not affiliated with Gelco, but we’ve installed and replaced their liner systems across the San Antonio area for years.

Which Gelco Models This Applies To

Gelco has manufactured a few different flue liner lines over the years, and the replacement path depends on which one you have. The two most common in San Antonio homes are the Gelco rigid stainless steel liners (usually 304 or 316 alloy) and the Gelco flexible corrugated liners used in retrofit applications where the chimney has bends or offsets. If you have a fireclay tile liner that was later relined with a Gelco product, that’s a third scenario we see regularly in older neighborhoods like Monte Vista and Alamo Heights.

The fastest way to identify your liner is to check the metal tag or stamp near the top termination cap. It usually shows the diameter in inches along with the alloy type. Common San Antonio sizes are 6-inch, 7-inch, and 8-inch for wood-burning fireplaces, though we see 5.5-inch liners on gas appliances and 10-inch or 12-inch on larger masonry fireplaces. If the tag is gone, we measure the existing liner at the top and at the firebox opening. That’s where the gotcha lives: a 7-inch ID liner and a 7-inch OD liner are different products, and mixing them creates a venting bottleneck that can push smoke back into the room. On Gelco flex liners, the corrugation depth also matters because aftermarket brands don’t always match Gelco’s pitch, and a mismatched connector can leak flue gases at the joint.

When it comes to OEM versus aftermarket for Gelco, our position is simple. For the liner body itself, we prefer Gelco-branded sections when they’re available, because the alloy spec is documented and the seams are built to a consistent tolerance. That said, a quality 316L stainless aftermarket liner from DuraFlex frequently performs just as well in San Antonio’s climate, and we’ve installed both without issues. The connectors and adapter rings are where we stay strict: mixing brands there invites fitment problems, so we match those to whatever liner system the home already has.

Signs Your Gelco Flue Liner Replacement Is Failing

• Flakes of metal or black residue falling into the firebox. This is usually the inner wall of a Gelco liner shedding scale after years of heating and cooling cycles. Once the protective surface breaks down, corrosion accelerates, and you’ll start seeing debris after every fire.
• Smoke backing up into the room when you light a fire. A cracked or collapsed liner section narrows the flue passage, and the chimney can no longer pull enough draft. In San Antonio, this often shows up on warmer winter days when the temperature difference between inside and outside is smaller, because draft relies on that temperature gap.
• A sulfur or “burnt metal” smell in the house after the fireplace has been used. This points to flue gases escaping through a seam or pinhole in the liner. Those gases include carbon monoxide, so treat this symptom seriously and stop using the fireplace until it’s inspected.
• Visible rust stains on the exterior chimney chase or water in the firebox after rain. A failed liner often pairs with a failed top plate or cap, and San Antonio’s spring thunderstorms will find every opening. Water intrusion plus a compromised liner equals rapid deterioration.
• Your last sweep report noted “spalling,” “gaps between flue tiles,” or “liner at end of life.” If a previous chimney company flagged tile deterioration behind the Gelco liner, the liner itself may have been masking a bigger structural issue. We camera-inspect every liner before recommending replacement, so you’re not paying to fix a liner when the real problem is the masonry behind it.

Replacement Cost & What’s Included

For a standard single-story San Antonio home with a straight flue, a Gelco liner replacement typically lands between $1,800 and $2,600 installed. Two-story homes, chimneys with offsets, and larger diameter liners push that to $2,800 through $3,400. The range comes down to three things: liner length (measured from the firebox to the termination cap), diameter (larger diameters cost more per linear foot in both material and handling), and whether we’re replacing just the liner or also the top plate, cap, and rain guard while we’re up there.

We give you a written quote before any work starts, and the price on that quote is the price you pay, no matter what we find once the old liner is pulled. The quote includes removal and haul-away of the old liner, installation of the new one, sealing at both terminations, and a camera inspection afterward so you can see the result for yourself. Every repair carries our 365-Day Done Right Promise in writing, with a free second visit if anything goes wrong within that year.

DIY or Call Us?

You can safely check a few things yourself: look for rust at the top of the liner from a ladder at the roofline (without getting on the roof), shine a flashlight up from the firebox to look for obvious collapse or debris, and note any of the symptoms above. That’s enough to know whether a call is warranted. What you shouldn’t do is pull the liner yourself. A Gelco liner in a masonry chimney is under tension when flex sections are involved, and the inside of a used flue is coated with creosote, which is the flammable tar buildup that makes chimneys a fire risk. Combine the two, and one slip means a chimney fire or a fall from a San Antonio roofline. We’ve also seen well-meaning homeowners damage the surrounding flue tiles while yanking out a stuck liner, which turns a $2,000 job into a $6,000 masonry rebuild. Flue liners are installed with a dedicated crew and proper sealing materials, and that’s equipment worth paying for. Call (254) 276-4116 if you suspect yours is failing, and we’ll camera it before quoting anything.

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