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 Silver Spring Owner’s Guide
Gelco flue liner replacement in Silver Spring typically runs $2,800 to $5,200 installed, depending on chimney height, diameter, and whether the existing liner pulls out cleanly or has to be cut out in sections. We stock Gelco-compatible stainless steel liner in the common diameters, and most replacements are completed in a single day once the inspection is done. If you’re seeing rust flakes in the firebox, smelling smoke in upstairs rooms, or your sweep just showed you a cracked liner on camera, you’re probably looking at this job.
Most Silver Spring homeowners discover their Gelco liner is shot during a routine sweep, especially in the older homes off Georgia Avenue and around Woodside Park where original clay flue tiles were retrofitted with stainless liners in the 1990s and 2000s. The liner doesn’t announce itself. It corrodes from the inside, pinholes open near the water table where condensation collects, and eventually you’re losing draft or worse, getting carbon monoxide spillage. Russell Haines has seen enough of these to know the difference between a liner that’s tired and one that’s dangerous. “Tell me what the chimney needs. Then we fix that. Nothing more, nothing less.”
Which Gelco Models This Applies To
Gelco manufactured several liner series over the years, and the part you need depends on what’s in your chimney now. The Gelco UL-listed flexible stainless liners, common in Montgomery County retrofits, came in 316Ti and 304 alloy grades with diameters from 3 to 12 inches. The critical spec is the inner diameter, measured at the thimble where the liner meets the appliance, not the outer wrap. We’ve pulled Gelco liners that were sold as “6-inch” but measured 5.5 inches true ID, which matters when you’re mating to a new insert or stove.
To identify your liner, look for the stamped metal tag near the top termination, usually visible from the roof. If the tag’s gone, we measure with a chimney camera and caliper. OEM Gelco liner is no longer manufactured, but we source replacement from the same foundries that supplied Gelco’s original stock, 316Ti alloy with the same .006 to .012 wall thickness depending on diameter. For most Silver Spring applications, a quality aftermarket equivalent matches OEM spec at lower cost and carries the same UL 1777 listing. We don’t use 304 alloy in exterior chimneys here; the freeze-thaw cycling and Maryland humidity chew through it faster than 316Ti.
Signs Your Gelco Flue Liner Replacement Is Failing
- Rust-colored staining on the chimney breast or ceiling. This means moisture is getting through pinholes or seam failures in the liner, condensing in the cooler outer cavity, and wicking into plaster. In Silver Spring’s humid summers, this accelerates once the protective oxide layer is breached.
- Smoke odor in upstairs bedrooms when the fireplace is not in use. A cracked or separated liner loses negative draft, allowing house air to reverse down the flue and carry creosote smell with it. We see this most in two-story colonials where the chimney runs through conditioned space.
- Visible cracks or gaps in the liner wall on camera inspection. The camera doesn’t lie. A circumferential crack at a joint, longitudinal splitting from thermal shock, or “alligatoring” of the metal surface means the liner’s structural integrity is gone. It may still draft today; it won’t when you need it most.
- Difficulty starting or maintaining a fire despite dry wood and open damper. A perforated liner leaks combustion air, killing draft. The fire smolders, creosote deposits increase, and the cycle worsens. We’ve traced “bad firewood” complaints to liner failure more times than you’d expect.
- Chunks of metal or rust debris in the cleanout or firebox. This is advanced failure. The liner is shedding material, often from the bottom section where acidic condensation pools. At this stage, continued use risks liner collapse or blockage.
Replacement Cost & What’s Included
For a typical Silver Spring single-flue chimney, Gelco-compatible liner replacement breaks down as follows:
| Component | Price Range |
|---|---|
| 316Ti stainless liner (material only, 20-25 ft typical) | $1,400 – $2,400 |
| Top plate, rain cap, and connector kit | $280 – $450 |
| Labor: removal, installation, insulation wrap | $1,000 – $2,200 |
| Level-2 camera inspection and photo report | Included |
| Total installed | $2,800 – $5,200 |
What drives the range: chimney height above roofline (steep pitches add labor), whether the old liner is intact enough to pull or must be demolished in place, and if the existing top plate is reusable. We price this upfront after inspection, not after we’re halfway in. The number on the estimate is the number on the invoice. Every liner replacement carries our 90-Day Done Right Promise in writing, and the liner itself comes with a lifetime manufacturer warranty when we install it.
DIY or Call Us?
There’s a honest line here. A homeowner can safely check the cleanout for debris, confirm the damper opens fully, and verify the cap isn’t clogged with leaves. What you cannot safely do is climb a steep roof in Silver Spring’s November rain, work inside a confined flue with sharp metal edges, or properly evaluate whether a liner with surface corrosion still meets UL thickness standards.
Liner replacement involves working at height, handling heavy stainless in tight quarters, and ensuring the insulation wrap is continuous, which is what prevents creosote ignition and keeps the liner from overheating. We’ve been called to fix DIY installs where the liner was upside-down (smooth wall should be interior), where insulation gaps created hot spots, and where an improper connection to a gas appliance produced CO spillage the homeowner couldn’t smell. If you’re competent with tools and comfortable on a roof, you might manage the removal. The installation and safety verification belong to someone who does it weekly. Call (301) 479-9806 and we’ll walk through what you’re seeing, no charge for the conversation.
FAQs
A properly installed 316Ti stainless liner should last 20 to 30 years in this climate, though we’ve seen premature failure in unlined exterior chimneys where condensation freezes and thaws against the metal. Annual sweeping and burning seasoned hardwood extends life significantly; burning wet wood or skipping maintenance can cut it to under 10 years. Call (301) 479-9806 for an exact quote - estimates are free.
Localized damage can sometimes be addressed with a stainless repair sleeve or HeatShield cerfractory sealant, but only if the remaining liner passes thickness gauge and the damage is accessible from top or bottom. If corrosion is generalized or the liner has separated at joints, replacement is the only sound option. We document this with camera footage you can see before you decide.
Most Gelco liner replacements are completed in one day, assuming standard height and no masonry rebuild needed. We arrive with the liner on the truck, sized from the prior inspection. Two-story homes with steep roofs or interior chimney runs may extend to a second day. We’ll tell you which situation you’re in before we start.
We stock 316Ti flexible liner in the diameters that cover 90% of Silver Spring homes, 5 to 8 inch, along with the termination kits and insulation. Uncommon sizes or rigid liner configurations typically arrive within two business days. Hearthstone Chimney Co. is an independent service provider, not affiliated with Gelco; we source compatible replacement from the same supply chain that served their original manufacturing.
Written by Russell Haines, Owner, Hearthstone Chimney Co. at Hearthstone Chimney Co., serving Silver Spring and nearby areas.





Before
After
Before
After
Before
After