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 Cleaning in Boulder, CO | Emberly Chimney Cleaners Boulder
Gelco chimney cleaning and repair in Boulder typically runs $180-$340 for a standard sweep with Level 2 camera inspection, and most Gelco cap or damper issues we see here trace back to Chinook wind damage or the city’s unique burn-action-day pattern. We’re an independent service company - not manufacturer-authorized - which means we source OEM Gelco parts when they fit and quality aftermarket components when they don’t, always with a written price before any work starts. Call (970) 598-0453 for a free estimate.
Why Boulder Residents Choose Us for Gelco Service
We’ve worked on Gelco systems across Boulder County since 2009, and we’ve learned what fails here that doesn’t fail the same way in Denver or Longmont. Corrine Halstead, our owner, grew up in Queens and came up through the heating and ventilation program at Manhattan’s Apex Technical School before heading west. She’s spent years on roofs from Mapleton Hill to Gunbarrel, and she still sketches flue diagrams in a worn notebook she keeps in the truck - a habit from her early days that helps her think through odd configurations before she quotes anything.
That background matters because Boulder’s chimneys are weird. The 5,430-foot elevation, the Chinook winds ripping off the Flatirons, the mid-century housing stock with original flue tiles that don’t match modern liner kits - none of this shows up in a Gelco catalog. We carry Gelco sales & service knowledge, but we apply it to Boulder’s actual conditions, not a generic installation manual. Our technicians are background-checked and uniformed, we text you when we’re on the way, and every job gets a documented photo record under Haven Standard Clause 4. The camera doesn’t guess. Neither do I.
We serve the full Boulder service area, from the unlined rubble-stone chimneys in Whittier to the gas inserts in newer builds near Chautauqua.
Common Gelco Chimney Cleaning Problems We Solve in Boulder

- Stainless liner seam separation in flex kits. Gelco flexible liner seams can separate or creosote-log at the joints after repeated high-intensity burns on Boulder County action days. The on/off burn pattern produces brittle, flaky creosote that packs into these seams differently than steady-use buildup. We inspect with a camera, remove the obstruction with poly brushes sized for this residue type, and reseal or replace the liner section if the seam has failed structurally.
- Multi-flue cap wind damage. In Table Mesa and Gunbarrel, Gelco multi-flue caps regularly lose mounting screws or suffer torn mesh from Chinook gusts exceeding 100 mph. Water and debris enter the flue, accelerating corrosion and creating blockages. We stock replacement caps and can upgrade to wind-directional models where downdraft is chronic.
- Top-sealing damper gasket failure. Gelco top-sealing damper gaskets degrade fast under Boulder’s 40°F Chinook temperature swings. The damper sticks open or leaks, producing false backdraft symptoms that homeowners mistake for a dirty flue. We diagnose this with a camera inspection - not a guess - and replace the gasket or the full damper assembly with OEM or matched aftermarket parts.
- Liner adapter gaps in unlined masonry. On unlined rubble-stone chimneys in Whittier and Mapleton Hill, Gelco liner adapters often don’t seat against irregular flue tile. Gaps let creosote and moisture bypass the liner, collecting in the masonry where you can’t see it. We document these gaps with camera footage and custom-fit transition pieces or recommend a full liner replacement when the masonry is too compromised.
- Crown and flashing freeze-thaw damage. Boulder’s dramatic temperature swings, especially those Chinook days where the thermometer jumps 40°F in hours, open hairline cracks in mortar crowns and separate flashing from the chimney stack. Water gets in, freezes, expands. We seal or rebuild crowns and reflash with materials sourced through our Haven buying network - DuraFlex, HeatShield, Gelco, Olympia Chimney, Famco, and Copperfield - to keep the price honest.
Before
AfterGelco Service in Boulder: What Local Conditions Mean for Your Equipment
Boulder’s mandatory wood-burning action days create a problem you won’t find in a generic chimney sweep guide. Many Gelco-equipped chimneys sit cold for weeks at a stretch, then get fired hard on the days burning is allowed. This stop-start pattern produces a brittle, flaky creosote - Stage 2 progressing fast to Stage 3 - that behaves nothing like the gummy, tar-like buildup from steady winter use. Our Boulder Chimney Cleaning & Sweep technique is calibrated for it: softer poly brushes that don’t glaze the residue onto the liner wall, slower rotation speed, and a camera check every ten feet to confirm we’re not pushing debris past a joint gap. In Martin Acres we serviced a 1960s ranch with a Gelco stainless flex liner and a multi-flue cap that had lost two screws in a recent Chinook event; the homeowner reported smoke smell even when the fireplace was off. We replaced the cap with a Gelco wind-directional model, swept the liner with poly brushes sized for the flaky creosote Boulder’s burn pattern produces, and sealed the crown where freeze-thaw had opened a hairline crack. The smoke smell stopped, and the next action-day fire drafted cleanly.
The altitude compounds everything. At 5,430 feet, combustion is less complete than even at Denver’s 5,280 feet. More unburned hydrocarbons make it up the flue. The creosote forms faster and harder. A chimney that might go two years between sweeps at sea level needs annual attention here - not because we’re selling harder, but because the physics are unforgiving.
Gelco Models & Products We Service in Boulder

We work on the full Gelco line: stainless steel flexible chimney liner kits, multi-flue chimney caps, single-flue caps with spark arrestors, and top-sealing damper systems. For Boulder homes with older or odd flue dimensions - common in the 1950s-1970s Table Mesa and Martin Acres stock - we carry adapter inventory and can source custom sizes through our Haven materials network. When the exact Gelco OEM part is available, we use it. When it’s obsolete or the lead time stretches past burn season, we specify quality aftermarket stainless that meets or exceeds the original spec. We don’t push brand loyalty over what actually fits your chimney.
Gelco Service Pricing in Boulder
Our Gelco chimney services in Boulder follow clear price ranges:
- Standard chimney sweep with Level 2 camera inspection: $180-$240
- Sweep with heavy creosote removal (Stage 2-3): $260-$340
- Gelco cap replacement (single-flue): $320-$480 installed
- Gelco multi-flue cap replacement: $450-$680 installed
- Top-sealing damper repair or replacement: $380-$620
- Crown sealing or minor repair: $280-$450
- Chimney waterproofing treatment: $340-$520
What drives cost: accessibility (roof pitch, chimney height), creosote stage, and whether we’re matching to existing Gelco hardware or retrofitting for an odd flue size. Every estimate is free, written, and delivered before work starts - Haven Standard Clause 1. We also offer a Free Second Opinion on any competitor’s written estimate. Call (970) 598-0453 for your exact quote.
Serving Boulder, CO - Our Local Coverage Area

We’re based in the Boulder area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs - Gelco Chimney Cleaning in Boulder
Yes. If the Gelco liner is intact and properly seated, we replace only the cap, matching to your existing flue size or upgrading to a wind-directional model if downdraft is chronic. We document the liner condition with a camera scan before we quote - no assumptions. Call (970) 598-0453 for a free estimate.
This is usually a pressure-differential issue, not a dirty flue. Boulder’s Chinook winds create powerful downdrafts along the Flatirons leeward slope that can override normal chimney draw. A Gelco wind-directional cap or a top-sealing damper upgrade as part of Chimney Repair in Boulder often solves it. We distinguish this from creosote-related draw problems with a camera inspection and a smoke-pencil test on site - so you don’t pay for a sweep you don’t need.
The on/off burn pattern produces brittle, flaky creosote that packs into liner joints and resists standard wire brushing. Our sweep protocol uses softer poly brushes and slower rotation, with camera verification every ten feet. Annual cleaning is more urgent here than at lower elevations with steadier use. Call (970) 598-0453 to schedule before the next action-day window.
We stock common Gelco sizes and carry adapters for many irregular flue dimensions found in Boulder’s mid-century and Victorian housing stock. For true custom sizes, we source through our Haven materials network with turnaround typically under a week - faster than most OEM direct orders.
Yes. We use vapor-permeable treatments applied below the cap line and above the roof flashing, masking Gelco components during application. The waterproofing breathes so trapped moisture escapes, but liquid water sheds. We document the liner and cap condition before and after under Haven Standard Clause 4.
Service Areas Near Boulder

We cover Boulder and surrounding communities including Gelco service in Niwot, Gelco service in Louisville, Lafayette, Erie, and Broomfield. Same independent service, same written-price-first standard, same camera documentation on every job.
Book Your Gelco Service in Boulder Today
Call (970) 598-0453 to speak with a live person - 24 hours a day, 7 days a week - and schedule your free estimate. We’ll send a background-checked, uniformed technician with a camera, a written price before any work starts, and a documented photo record when it’s done. Backed by our 365-Day Done Right Promise.
Written by Corrine Halstead, Owner at Emberly Chimney Cleaners Boulder, serving Boulder since 2009.





Before
After
Before
After