Gelco Flue Liner Replacement in Houston, TX

Gelco Flue Liner Replacement: The Houston Owner’s Guide

Gelco flue liner replacement in Houston typically runs $2,800 to $5,400 installed, depending on chimney height, diameter, and whether the original liner was a Gelco ProFlex, Gelco UltraPro, or an earlier Gelco stainless series. We stock Gelco-compatible liners and termination caps on our trucks, and most Houston replacements are completed in a single day. Most owners discover the problem during a routine sweep when our camera catches the telltale gaps, or they notice water staining on the firebox after a hard Gulf Coast rain pushes through a cracked seam.

Call (877) 516-5603

Which Gelco Models This Applies To

Gelco has produced three main liner families over the past thirty years, and knowing which one you have changes everything about the replacement.

The Gelco ProFlex series, common in Houston homes built from the mid-1990s through the late 2000s, is a corrugated 316Ti stainless liner with a distinct ribbed wall. You’ll find the ProFlex label stamped on the top termination cap or, if that’s been replaced, on a tag left at the thimble connection. Diameters run 3 to 10 inches, but the Houston market saw heavy use of 6-inch and 8-inch sizes for masonry fireplaces converted to gas inserts.

The Gelco UltraPro, introduced around 2010, switched to a smoother-wall design with a heavier 316 alloy and a different collar connection at the top. The UltraPro termination cap is not interchangeable with ProFlex. We have found this out the hard way on jobs in Bellaire and West University where a previous installer forced the wrong cap on and created a gap that collected condensation.

Earlier Gelco smooth-wall rigid liners, mostly pre-1995, used a thicker gauge but shorter section lengths. These are harder to source as OEM today. We typically match these with an Olympia Chimney or DuraFlex equivalent in 316L or 316Ti, depending on the appliance type and venting temperature. The critical spec is the inner diameter, measured at the thimble where the liner enters the smoke chamber, not the outer diameter of the corrugated wrap.

A compatibility gotcha we see in Houston: some ProFlex liners were installed with a flex-to-rigid adapter at the base for woodstove connections. That adapter is often where the failure starts, and it requires a Gelco-specific part or a carefully matched aftermarket equivalent. Generic adapters from the hardware store do not seat correctly and will leak exhaust.

Signs Your Gelco Flue Liner Replacement Is Failing

• Water stains on the firebox walls or hearth extension. Gelco liners, especially ProFlex with its corrugated valleys, can develop pinhole corrosion at the low points where acidic condensation collects. In Houston’s humidity, this accelerates. The water you see is often the last symptom, not the first.
• White or orange powder on the liner walls visible from below. This is efflorescence or rust oxidation bleeding through a crack. On a Level-2 camera inspection, we look for this at the joints between sections, where the male-female overlap has worked loose from thermal cycling.
• Smoke odor in the house when the fireplace is not in use. A separated Gelco liner joint or a failed top termination seal allows downdraft to push chimney air into the living space. We traced one persistent odor in a Memorial home to a ProFlex cap that had lost its storm collar seal, nothing more, but the homeowner had lived with it for two winters.
• Chunks of clay tile in the firebox. If your chimney was originally clay-lined and the Gelco liner was installed as a retrofit, liner collapse can expose the old flue. Those clay fragments mean the Gelco is no longer protecting the masonry, and exhaust gases are cooling against the brick before reaching the top.
• The liner has visible sag or dip in the middle run. Gelco ProFlex requires proper tensioning during installation. A sag means the top plate has slipped or the bottom support is failing. Either way, the liner is not drafting correctly, and creosote will pool at the low point.

Replacement Cost & What’s Included

What drives the range: chimney height, roof pitch and accessibility, whether the existing liner pulls out cleanly or has to be cut and extracted in pieces, and whether the top plate and flashing need replacement too. We price this upfront, after inspection, not after we’ve started. The number on the estimate is the number on the invoice.

Every Gelco liner replacement we install carries our 90-Day Done Right Promise in writing. If the draft is not right, if a joint separates, if water gets in, we come back. No paperwork to dig up, no argument about whose fault it was. We also document the completed job with photos of the new liner run and the top termination, so you have a record.

DIY or Call Us?

There is one thing a homeowner can safely check: look up the flue from the firebox with a flashlight for obvious gaps, sag, or debris. If you see clay chunks or daylight where the liner should be continuous, you have your answer.

Everything else belongs to a trained sweep. Pulling a Gelco liner requires controlled tension release, proper roof anchoring, and knowledge of how the sections couple. Installing the replacement means sizing the length exactly, seating each joint fully, and pressure-testing the run. A mis-seated ProFlex joint will not show itself until the first heating season, when creosote finds the gap and you have a chimney fire risk. The top termination must meet Houston wind and rain loads, which a generic cap will not.

We are not affiliated with Gelco Manufacturing. We are an independent chimney service that has worked with their products long enough to know where they succeed and where they need attention. If you suspect your Gelco liner is failing, call (877) 516-5603. A live person answers, and we can usually inspect within 48 hours.

FAQs