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 Chimney Liner & Rebuild in Allentown: What to Know First
We provide independent Gelco chimney liner and rebuild service in Allentown, with most jobs completed in a single visit and pricing agreed before we start. A typical Gelco stainless steel liner replacement runs $2,800-$4,200, while a partial chimney rebuild starts around $3,500; we don’t quote low to get in the door, then find “surprises.” This page is for Gelco owners in Allentown who’ve been told they need liner work or masonry repair and want a second opinion they can verify with their own eyes, not a sales pitch. Call (610) 632-1394 - a live person answers, 24 hours a day.
How Gelco Products Fail - and How We Fix Them
- Gelco UL stainless steel liner tubes (3003 and 316Ti alloys): In Allentown’s freeze-thaw climate, the 3003 series develops pinhole corrosion at the welds faster than 316Ti, especially when connected to older oil-fired boilers that vent slightly acidic condensate. We see this most in homes built 1960-1985 in the West End. We replace with Gelco 316Ti or shift to DuraFlex 316Ti if the flue run has multiple offsets, since DuraFlex handles tight bends without the stress fractures we’ve found in Gelco’s flexible line after five to seven years of thermal cycling.
- Gelco flexible liner (Model GF series): The GF’s corrugated walls trap creosote in the valleys, and when Allentown homeowners burn seasoned hardwood at too low an air setting - common with airtight inserts - the buildup compresses and restricts draft. We’ve pulled GF liners with 40% flow reduction that passed a basic visual inspection. Our fix: camera-documented assessment, then either mechanical cleaning with rotary polypropylene chains (warranty-safe, no wire brushes that score the alloy) or replacement with a rigid Gelco UL tube if the GF has thinned at the elbows.
- Gelco liner top plate and collar assemblies: The stamped-steel top plates sold with mid-2000s Gelco kits rust through at the fastener holes where the storm collar meets the plate. Water tracks down the outside of the liner, pools at the thimble, and rots the surrounding masonry from the inside. We replace with Gelco’s current galvanized top plate or upgrade to a Copperfield stainless cap assembly if the homeowner wants the longer corrosion resistance - and we always re-point the thimble area with high-temp refractory mortar, not standard Type N.
- Gelco Heat-Fab Saf-T Liner (the black painted line): The baked-on black finish looks sharp from the hearth, but we’ve found it blisters and flakes inside the flue after repeated over-firing, exposing the underlying 430 alloy to rapid oxidation. In Allentown, where many homeowners run their stoves hard during February cold snaps, this can cut liner life by half. We strip and assess; if the 430 is still structurally sound, we can sleeve with a 316Ti insert, but if the wall has thinned below 0.005 inch, replacement is the only safe call.
- Gelco oval-to-round adapters and offset connectors: These stamped fittings take the stress in any liner system, and Gelco’s older snap-lock versions (pre-2012) can work loose when the chimney shifts during Allentown’s spring thaw cycles - the clay flue tiles expand and contract, levering against the adapter. We find gaps that leak combustion gases into the smoke chamber. Our fix: replace with Gelco’s current welded-seam adapter, secured with refractory screws and sealed with HeatShield Cerfractory foam at the joint. No more snap-lock. Done right, and we stand behind it.
Our Gelco Chimney Liner & Rebuild Process
- 1
Call and schedule. A live person answers, day or night. We ask what you’re burning, what you’re seeing (stains, smell, draft problems), and whether you’ve had prior liner work. We book a Level-2 inspection with camera.
- 2
Camera inspection and verdict. Russell Haines or one of our techs runs a 360-degree camera the full flue length. You see the footage on a tablet as we go. We mark cracks, thinning, creosote buildup, and masonry damage. You get a plain-English verdict: repair, replace, or monitor - and we tell you when work can safely wait.
- 3
Parts decision: OEM Gelco or quality alternative. If Gelco still makes the exact part and it’s the right fit, we quote it. If Gelco has discontinued a fitting (the pre-2012 snap-lock adapters, for instance), we source compatible DuraFlex or HeatShield components that meet or exceed UL 1777. We explain the trade-off before you decide.
- 4
The repair. Background-checked, uniformed technicians arrive with the agreed parts. Most Gelco liner replacements and partial rebuilds finish in one day. We protect floors and furniture, work with dust containment, and don’t leave until the flue is tested for draft and leak-tightness.
- 5
Documentation and guarantee. You get photos of the completed work, a written condition report, and our 90-Day Done Right Promise - in writing, no arguing. If it’s not right, we make it right. The number on the estimate is the number on the invoice.
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Cleanup and follow-up. We haul away old liner and debris. A week later, we call to confirm performance. No automated survey - a real person, checking that the draft is pulling and the hearth area is dry.
What Gelco Chimney Liner & Rebuild Costs in Allentown
| Service | Typical Range | What Moves the Price |
|---|---|---|
| Gelco stainless steel liner replacement (straight flue, 316Ti) | $2,800 - $4,200 | Flue height, number of appliances connected, access (steep roof, tight chase) |
| Gelco flexible liner replacement (GF series, with offsets) | $3,200 - $4,800 | Degree of offset, need for demolition of surrounding masonry, liner diameter |
| Partial chimney rebuild (above roofline, with Gelco liner) | $3,500 - $6,500 | Linear feet of masonry, matching historic brick, need for crown replacement |
| Full chimney rebuild (from roofline down, with new Gelco liner) | $8,000 - $14,000 | Height, scaffolding requirements, hearth extension modifications |
| Gelco liner top plate/collar replacement only | $650 - $1,200 | Roof access, condition of existing storm collar, thimble repair needed |
| Heat-Fab Saf-T Liner assessment and possible sleeve | $1,800 - $3,400 | Extent of coating failure, underlying alloy condition, flue diameter |
These are real Allentown numbers, not bait-and-switch estimates. We price by the job, not by the hour, so a stubborn liner pull doesn’t cost you extra. Every estimate includes the camera inspection and photo report. Call (610) 632-1394 for an exact quote - estimates are free.
Why Allentown Homeowners Call Hearthstone Chimney Co. for Gelco Work
We’ve worked chimneys across Allentown for over 42 years, including the older homes near West Park where the clay flue tiles date to the 1920s and the brick is soft enough to crumble under a dull tuckpointing job. The chimney doesn’t care what it looks like from the street. We check what’s inside. Our Level-2 inspections end with photos you can see and a plain-English verdict - documented like an engineer, explained like a craftsman. If your Gelco system needs a part that’s discontinued, we don’t disappear; we source quality alternatives from DuraFlex or HeatShield and warrant the result the same as OEM. The 90-Day Done Right Promise means if it’s not right, we come back. No paperwork to find, no arguing. A square deal: no surprises on the bill.
FAQs
No. As an independent Gelco service provider, we follow UL 1777 installation standards and Gelco’s published specifications, which preserves warranty coverage on materials. Using a non-authorized technician does not void a Gelco warranty unless the work itself is defective - and our 90-Day Done Right Promise covers exactly that risk. Call (610) 632-1394 if you have warranty paperwork you’d like us to review.
Most Gelco 316Ti tubes and current top plates are readily available; some pre-2012 fittings like the snap-lock adapters have been discontinued. When Gelco doesn’t make it anymore, we source compatible DuraFlex or HeatShield components that meet the same UL standards, explain the substitution before you approve it, and warrant the repair fully. Call (610) 632-1394 to check parts availability for your specific model.
We decide with a camera. Surface creosote or a loose top plate gets repaired; wall thinning below 0.005 inch, multiple cracks, or weld corrosion gets replaced. We’ll show you the footage and tell you which category you’re in - and if the condition is borderline, we’ll say so and recommend a re-inspection interval rather than push unnecessary work. Call (610) 632-1394 to schedule the camera inspection.
Most straight flue replacements finish in one day; jobs with multiple offsets, a buried flue in a chase, or combined rebuild work may run two days. We tell you the timeline when we quote, and we don’t book more jobs than we can finish. We’ll be there when we say. Call (610) 632-1394 to check current scheduling.
A compromised liner leaks combustion gases - carbon monoxide among them - into wall cavities and living spaces, and creosote leaking through cracks can ignite in the surrounding masonry. That said, not every crack is an emergency. Our camera inspection tells you whether you have months or need action now. When work can safely wait, we say so. Call (610) 632-1394 for an honest assessment.
Written by Russell Haines, Owner, Hearthstone Chimney Co. at Hearthstone Chimney Co., serving Allentown and nearby areas.





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