Gelco Flue Liner Replacement: The San Francisco Owner’s Guide
A Gelco flue liner replacement in San Francisco typically runs between $2,800 and $4,200 installed, depending on the height of your chimney and the diameter of the liner. We stock Gelco-compatible stainless steel liners in the common 6-inch and 8-inch diameters on our trucks, and most replacements are completed in a single day. If you’re noticing bits of clay tile in your firebox or a persistent smoky smell in your living room, your liner has likely begun to fail.
San Francisco’s coastal climate does a particular kind of damage to flue liners. The fog that rolls in off the Pacific carries salt that accelerates corrosion in stainless steel, and the thermal shock of heating a cold, damp chimney on a July evening in the Richmond District can stress a liner that was already marginal. We’ve replaced Gelco liners in Victorians from Noe Valley to the Outer Sunset where the original installation was sound but the conditions simply wore it down faster than the manufacturer anticipated.
Which Gelco Models This Applies To
Gelco has manufactured flue liners under several series names over the decades, and the label on your existing liner is the first place to look. The Gelco Ultravent and Gelco Pro series are the two most common in San Francisco homes built between 1960 and 1995. Ultravent liners carry a part number starting with “UV-” followed by the diameter and length; Pro series use “GP-“. If your label is illegible, measure the inner diameter at the thimble connection and note whether your chimney is a straight shot or has an offset, which Gelco addressed with their adjustable elbow kits (part GP-EL45).
Here is where compatibility gets tricky. Gelco’s early Ultravent used a slightly thinner 316 alloy in pre-1985 production, while later runs and all Pro series moved to 316Ti with titanium stabilization. A direct OEM replacement from Gelco is still available for most sizes, but we also source quality aftermarket equivalents from Olympia Chimney that meet the same UL 1777 standard and carry a comparable warranty. For most San Francisco homeowners, the aftermarket route saves roughly $400-$600 on material cost with no sacrifice in performance. We match the alloy grade to your application, not just the brand name.
Hearthstone Chimney Co. of San Francisco is an independent service provider with no affiliation to Gelco. We work with their products because they were well-engineered and because many San Francisco chimneys were originally fitted with them.
Signs Your Gelco Flue Liner Replacement Is Failing
- Clay debris in the firebox or hearth. When a Gelco liner separates at the seams or corrodes through, the original clay flue tiles behind it begin to flake and fall. If you’re sweeping up sandy red fragments after a fire, the liner is no longer containing the byproducts of combustion.
- Smoke backup on startup or windy days. A compromised liner loses the smooth draft surface that draws smoke upward. In San Francisco’s variable pressure systems, especially near the wind corridors of Twin Peaks or the Presidio, a failing liner shows itself first as intermittent smoke spillage that seems to come and go with the weather.
- White or orange staining on exterior brickwork. This is moisture and creosote acids migrating through cracks in the liner, then leaching through the mortar joints. The white is efflorescence; the orange is rust from the liner itself degrading. Both mean the barrier between fire and structure is breached.
- Acrid, persistent odor even when the fireplace is cold. A sound liner contains the smell of accumulated creosote. When it fails, those volatile compounds seep into the living space through gaps in the surrounding masonry. Homeowners in Pacific Heights have described it as a “chemical campfire” smell that air fresheners cannot mask.
- Visible gaps or waviness in the liner when viewed from the top. If you can safely shine a light down your flue, a Gelco liner in good condition presents as a smooth, continuous cylinder. Bulges, separations at the riveted seams, or sections that look like they’ve shifted downward indicate the support system has failed and the liner is collapsing under its own weight.
Replacement Cost & What’s Included
| Component | Typical Range |
|---|---|
| Gelco-compatible stainless liner (material only) | $1,200 - $2,000 |
| Insulation wrap and top termination | $400 - $650 |
| Labor: removal, installation, sealing | $1,000 - $1,400 |
| Level-2 camera inspection and documentation | $250 - $350 |
| Total installed replacement | $2,800 - $4,200 |
What moves the price within that range is straightforward. A straight chimney on a two-story Marina District cottage with easy roof access sits at the lower end. A three-story Edwardian in Noe Valley with a steep pitch, an offset flue, and a cramped attic space requires more labor, more custom cutting, and sometimes a second technician for safe material handling. We price every job in person after inspection, not over the phone from a script. The number on your written estimate is the number on your invoice. Our 90-Day Done Right Promise covers the installation in writing with no arguing; if the draft isn’t right or a seam weeps smoke, we return and make it right.
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, debris, or liner collapse. Beyond that, flue liner replacement is not a DIY project. The work involves working at height on a pitched roof, handling lengths of stainless steel that can cut like a razor, and properly insulating and sealing a system that must contain 2000-degree gases inches from combustible framing. An improperly supported liner can collapse during the first heating season. An uninsulated liner in a San Francisco chimney cools too quickly, condenses creosote, and creates a fire hazard the homeowner cannot see.
We carry Gelco-compatible liners, insulation, and termination hardware on our trucks. Most jobs are completed in a single visit. Call (855) 408-5567 for a free estimate and a time that works for you.
FAQs
A properly installed stainless steel flue liner in San Francisco typically lasts 15 to 25 years, though the coastal salt air and frequent thermal cycling can shorten that toward the lower end. We’ve replaced Gelco liners in homes near the Great Highway that showed significant corrosion at 12 years, while inland installations in the Mission have held 20-plus. Annual inspection is the only way to know where yours stands. Call (855) 408-5567 to schedule a Level-2 camera inspection.
Small, accessible gaps in a Gelco liner can sometimes be addressed with a stainless repair sleeve or HeatShield resurfacing if the damage is localized and the surrounding liner is sound. However, seam separation, widespread corrosion, or any compromise in a liner that has already served 15 years means replacement is the prudent choice. We document the condition with photos you can see and give you a plain-English verdict, not a sales pitch. Call (855) 408-5567 for a free second opinion on any written estimate.
Most Gelco flue liner replacements are completed in one day, typically 4 to 6 hours of on-site work. We arrive with the liner cut to length based on our pre-measurement, remove the failed liner, install and insulate the new one, seal the top and bottom connections, and run a final camera inspection to verify the fit. You’ll have photos and a written report before we leave. Call (855) 408-5567 to book a date.
We stock Gelco-compatible stainless steel liners in 6-inch and 8-inch diameters, the two sizes that cover roughly 90 percent of San Francisco residential chimneys. For less common sizes or custom offsets, we order from our supplier with a 2 to 3 business day turnaround. We do not ask you to wait weeks for a part that your heating system depends on. Call (855) 408-5567 to confirm availability for your specific chimney.
If the flue isn’t right, the fire isn’t right. Everything else follows from that.
Warren Eckhart grew up in the Outer Sunset, two blocks from where the fog rolls in off the Great Highway, and he has spent the better part of thirty years climbing up onto the rooftops of this city’s Victorian and Edwardian homes. He learned the mechanical side of the trade through the Building and Construction Technology program at City College of San Francisco, then spent his early years working alongside an older sweep who had been servicing Mission District fireplaces since the 1970s. Warren is known throughout the Richmond and Noe Valley for his methodical inspections and his refusal to sign off on a flue he isn’t satisfied with.
When you’re ready to stop wondering about your chimney and start knowing it’s done right, call Hearthstone Chimney Co. of San Francisco at (855) 408-5567. A live person answers 24 hours a day, 7 days a week. We’ll schedule a free estimate, show up when we say, and back the work with our 90-Day Done Right Promise in writing. No surprises on the bill. No arguing if something needs adjustment. Just the job done correctly, the way a chimney in this city deserves.
Written by Warren Eckhart, Owner & Master Sweep, Hearthstone Chimney Co. of San Francisco at Hearthstone Chimney Co. of San Francisco, serving San Francisco and nearby areas.