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 Flue Liner Replacement: The McKinney Owner’s Guide
Gelco flue liner replacement in McKinney typically runs $2,800-$5,400 installed, depending on chimney height, diameter, and whether the existing liner pulls cleanly or has to be cut out in sections. We stock Gelco-compatible stainless steel liner in common diameters from 5″ to 8″ and can usually inspect, measure, and schedule replacement within 48 hours. Most McKinney homeowners discover their Gelco liner is failing after a Level 2 camera inspection reveals cracked seams, separated collars, or pinhole corrosion that wasn’t visible from the firebox - often during a routine sweep of a home bought in the 2015-2020 building boom, when Gelco liners were spec’d heavily in Collin County new construction.
Which Gelco Models This Applies To
Gelco’s stainless steel flue liner line breaks into two main series you’ll find in McKinney homes: the original Gelco standard-wall 316Ti alloy liners, common in builds from roughly 2008-2016, and the later Gelco Pro with heavier 316L construction and pre-crimped male-female couplings that seat without field welding. The difference matters because collar dimensions changed. Early standard-wall liners used a 1.5″ overlap coupling that can loosen after repeated thermal cycling in Texas heat, while Pro-series couplings seat deeper and hold better but require exact diameter matching.
To identify yours: look for a stamped model tag at the top termination, usually visible from the roof, or check for a paper label left inside the firebox throat during original installation. If neither survives, we measure wall thickness and coupling depth with a bore gauge during camera inspection. OEM Gelco parts are available through Haven’s buying network, but we also source compatible 316Ti and 316L liner from Olympia Chimney and DuraFlex when the original Gelco SKU is back-ordered or discontinued - which happens more than manufacturers admit. The aftermarket equivalent carries the same 20-year thermal warranty when installed to NFPA 211 standards, and we document the source in your written scope.
Signs Your Gelco Flue Liner Replacement Is Failing

- White or orange staining on exterior brick below the chimney crown. This means exhaust is escaping through a seam crack or pinhole in the Gelco liner, condensing on the cooler outer brick. In McKinney’s clay-heavy soils, that moisture accelerates spalling on the freeze-thaw cycle even when winters stay mild.
- Smoke smell in upstairs rooms when the fireplace is not in use. A separated collar or cracked tee-body lets downdraft carry flue gases into wall cavities. We see this often in two-story homes near Adriatica, where chimney height and roof pitch create negative pressure zones.
- Chunks of rust or metal flakes in the firebox after a sweep. 316Ti resists acid corrosion well, but the weld zone at each coupling collar is the weak point. Once pitting starts at a heat-affected zone, the liner wall thins faster than the rating suggests.
- Visible gaps or daylight through the liner wall on camera inspection. This is the definitive finding. NFPA 211 calls any breach in the liner an immediate repair item because it breaks the containment path for sparks and carbon monoxide.
- Water in the firebox after rain, with no crown or cap damage visible. A failed liner lets water track down the annular space between liner and clay flue tile, then pool where the tee meets the smoke chamber. The liner is supposed to be the waterproof path; when it’s not, everything downstream rots.
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AfterReplacement Cost & What’s Included
| Scope | Price Range |
|---|---|
| Gelco liner replacement, single-story chimney (up to 18′ flue) | $2,800-$3,600 |
| Gelco liner replacement, two-story chimney (18’-28′ flue) | $3,400-$4,500 |
| Cut-and-remove failed liner (seized or collapsed) | Add $400-$800 |
| Smoke chamber parging (required if parge coat is degraded) | Add $600-$1,100 |
| New Gelco or compatible top plate and rain cap | $280-$450 (included in most replacements) |
What drives the range: chimney height, liner diameter, and whether the existing Gelco liner pulls out intact or has to be extracted in pieces with a retrieval tool. Every replacement includes NFPA 211 Level 2 camera inspection before and after, a written scope with line-item pricing signed before work starts, and a documented photo record under Haven Standard Clause 4. The liner itself carries a 20-year thermal warranty; our labor is backed by the 365-Day Done Right Promise. Materials come through Haven’s buying network - we don’t markup parts to hide labor costs.
DIY or Call Us?

There’s one thing a McKinney homeowner can safely check: shine a flashlight up the flue from the firebox and look for obvious gaps, rust streaks, or missing sections of liner. If you see any of those, stop there.
Everything past visual inspection is where DIY goes wrong. Gelco liner replacement requires working on a steep roof with full fall protection, cutting the old liner to length with a metal chop saw, and seating the new liner under proper tension so thermal expansion doesn’t unseat the top termination. The real risk isn’t the tools - it’s what you can’t see. A liner that looks seated can gap at the collar, venting carbon monoxide into the home for months before anyone notices. NFPA 211 requires a pressure test and camera verification; we include both as standard. The camera doesn’t lie, and neither does the written quote.
Corrine Halstead grew up in Queens and learned the fundamentals at Apex Technical School in Manhattan before the trade brought her south. She’s spent the better part of her career running a brush and camera through fireboxes across Collin County, including a stretch of older homes near McKinney’s Historic Downtown district that taught her more about deteriorating mortar joints than any classroom could. She’s known around McKinney for showing customers the camera footage before quoting a single dollar, and for writing the scope and price on paper before anything gets scheduled.
Level Two Chimney McKinney is independently owned and operated, not affiliated with Gelco. We source Gelco-compatible materials through Haven’s buying network alongside DuraFlex, HeatShield, Olympia Chimney, Famco, and Copperfield products.
FAQs
A properly installed Gelco 316Ti or 316L liner should last 20-30 years, but we’ve seen failures at 12-15 years in McKinney homes where the original installer skipped the insulation wrap or used an undersized liner that ran too hot. The thermal cycling from Texas summer attic heat to winter firebox temperatures accelerates weld-zone fatigue. Annual inspection catches it before breach. Call (469) 429-2623 for a free estimate - estimates are free.
Localized cracks can sometimes be addressed with HeatShield cerfractory foam resurfacing if the damage is limited to a short section and the liner wall thickness is still within spec. But Gelco’s corrugated design makes spot repair unreliable - the crack usually indicates systemic thinning at the corrugation peaks. We won’t recommend repair without camera evidence you can see yourself, and we’ll tell you plainly when replacement can wait versus when it can’t. Call (469) 429-2623 for a free estimate - estimates are free.
Most Gelco liner replacements in McKinney are completed in one day, assuming the existing liner pulls cleanly and no smoke chamber rebuild is needed. A seized liner that has to be cut and extracted in sections adds a second day. We book morning starts so the crew isn’t rushing the final camera verification. Call (469) 429-2623 for a free estimate - estimates are free.
We keep 5″, 6″, 7″, and 8″ diameter Gelco-compatible 316Ti and 316L liner on the truck in standard 25′ and 35′ coils, along with termination plates, tee-bodies, and collar adapters. Odd diameters or 40’+ runs require a next-day pull from Haven’s Dallas-Fort Worth warehouse. We measure during inspection so material is on-site before the crew arrives. Call (469) 429-2623 for a free estimate - estimates are free.
Ready to see what your flue actually looks like? We’re Level Two Chimney McKinney, and we’ve inspected more than 38,000 chimneys since 2009 - every one with a written price before work started and a documented photo record when it was done. Calls are answered live, 24 hours a day. Bring us any competitor’s written estimate for a free second opinion.
Written by Corrine Halstead, Owner, Level Two Chimney McKinney at Level Two Chimney McKinney, serving McKinney and nearby areas.



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