Masonry repair
Sweep & inspection
Caps & crowns
Flue relining
Gas fireplace serviceLevel 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.
DuraFlex Gas Fireplace Repair in Marietta: What to Know First
DuraFlex gas fireplace repair in Marietta typically runs $220 – $480 for most common fixes (thermocouples, gas valves, pilot assemblies, venting corrections), and we can usually have your fireplace running again in one visit. We’re Hadley Chimney Marietta, an independent DuraFlex service provider – not a manufacturer rep – so we diagnose what’s actually failing and give you a written price before any work starts. If you own a DuraFlex direct-vent or B-vent gas fireplace and something’s acting up, call (762) 249-4619 and a live person will answer.
This page is for Marietta homeowners with DuraFlex venting or gas fireplace components who want straight answers on failure patterns, repair costs, and whether a fix is worth doing or if replacement makes more sense.
How DuraFlex Products Fail – and How We Fix Them
DuraFlex makes solid venting products, but gas fireplace systems in Marietta see specific failure patterns. Here’s what we actually find on service calls, including the stuff the manufacturer’s spec sheets won’t tell you.
- DuraFlex DirectVent Pro co-axial pipe seal degradation at the horizontal termination. Marietta’s humid summers and wet winters work on the silicone joint seals where the inner exhaust pipe meets the outer intake pipe at the wall or roof cap. When that seal breaks down, exhaust gases can recirculate into the intake air, which trips the oxygen depletion sensor and shuts down the fireplace. We replace the termination gasket and re-seal the joint with high-temp silicone rated for direct-vent applications, then test with a digital gas sniffer at every joint before we call it done.
- DuraFlex AL29-4C stainless flex liner sagging inside the existing B-vent chase. In many older Marietta homes – especially the craftsman houses off Whitlock Avenue that were built before direct-vent units became standard – gas fireplaces are vented through original masonry or B-vent chimneys using a DuraFlex flexible liner. Over time, the liner’s support straps loosen, creating a low spot where condensate pools. That acidic condensate eats through the stainless over a few seasons, and we find pinhole leaks at the lowest curve. We re-support the liner, patch or replace the affected section, and verify proper slope with a borescope camera, so you see photos of the fix.
- DuraFlex FasNSeal single-wall vent pipe gasket blowout at appliance adapter connections. The FasNSeal line uses a proprietary internal gasket system at the appliance adapter where the vent pipe meets the fireplace collar. After years of thermal cycling (fireplace goes from cold to 400+ degrees in minutes), those gaskets get brittle and crack. You’ll smell a faint exhaust odor near the unit, or the CO detector in the room will act up. We pull the adapter, replace the gasket set with genuine DuraFlex parts, and torque the clamp to manufacturer spec. It’s a small fix – usually $180 – $300 – that gets mistaken for a much bigger problem if someone’s just guessing.
- DuraFlex direct-vent wall thimbles installed with improper clearance in finished basements. This one’s common in newer Marietta builds near Kennesaw Mountain, where basements are finished after the original fireplace install. The wall thimble – the metal sleeve that protects combustible framing around the vent pipe – gets buried behind drywall or insulation. When that happens, it can’t radiate heat properly, and the wall gets dangerously hot around the vent. We open the wall, verify clearances against DuraFlex’s installation specs, fix the framing if needed, and document it with photos. This is a fire-safety repair, not a cosmetic one.
- DuraFlex liner terminations missing or failing storm collars and flashing at the chimney chase top. Where the flex liner exits the top of a prefab chase or masonry chimney, the storm collar and top plate keep rain from running down the outside of the pipe and into your chase. Marietta gets about 50 inches of rain a year, and a failed storm collar means water eventually reaches the fireplace itself – rusting the burner, shorting the gas valve wiring, and inviting mold inside the chase. We replace the storm collar and top plate, re-flash properly, and check the chase pan while we’re up there. If the chase pan is rotted through, you’ll see it in the photos we send before we quote the full repair.
Styles & brands we work with





Our DuraFlex Gas Fireplace Repair Process
Here’s exactly what happens when you book a DuraFlex repair with us in Marietta, from the first call to the final walkthrough.
- 1
You call (762) 249-4619. A live person answers – not a phone tree. We ask what the fireplace is doing (or not doing), whether it’s a DuraFlex direct-vent, B-vent, or fireplace insert, and what the symptoms are. We schedule a visit window that’s tracked, not guessed at.
- 2
We show up and do a full diagnostic, not just a parts swap. Techs check the gas valve operation, pilot assembly, thermocouple or thermopile output, wiring continuity, venting connections, and firebox condition. On DuraFlex systems, venting gets as much attention as the gas components, because vent issues cause most no-heat and shutdown calls.
- 3
We send you photos of what we find. Before recommending anything, we document what’s failing – a cracked gasket, a scored thermocouple, a blocked vent run – and send it to your phone. Cory Mitchell’s standing rule: “I’ll send you the photo first – then we’ll talk about what it means.”
- 4
You get a written price before we touch anything. No verbal estimates, no “we’ll see when we get in there.” The price covers parts and labor. If the parts decision matters (OEM DuraFlex vs a quality aftermarket equivalent), we explain the difference and let you choose.
- 5
We do the repair, then test it properly. Every repair gets a full operational test – flame pattern check, thermocouple response, vent draft verification with a draft gauge, and carbon monoxide spot-check at the fireplace opening and nearby vents.
- 6
You get photos and a written guarantee. Our work carries a 365-day written guarantee. If the repair fails within a year, we come back free. Simple as that.
See the difference
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AfterWhat DuraFlex Gas Fireplace Repair Costs in Marietta
Here are realistic price ranges for the DuraFlex repairs we do most often in this market. These are total prices – parts and labor, the written quote you approve before we start.
- Thermocouple or thermopile replacement: $215 – $340
- Pilot assembly replacement (OEM DuraFlex pilot): $275 – $425
- Gas valve replacement: $380 – $680
- Direct-vent gasket or seal replacement: $180 – $320
- Flex liner section replacement (2 – 4 feet): $340 – $720
- Full venting inspection with camera + written report: $95 – $175
What moves the price: whether parts are OEM DuraFlex or an accepted aftermarket equivalent (OEM runs 20 – 40% more), how accessible the venting is (finished basements cost more to work in), and whether we discover additional vent failures during the diagnostic. We’ll tell you exactly what you’re paying for and why. Call (762) 249-4619 for a free estimate – if you’re looking at a repair, we’ll help you figure out whether it makes sense to fix or replace.
Why Marietta Homeowners Call Hadley Chimney Marietta for DuraFlex Work
We’ve been doing chimney and fireplace work out of Marietta since 2003. The company has two decades of local service behind it, and Cory Mitchell and his crew have worked everything from newer builds near Kennesaw Mountain to older craftsman houses where the liner hasn’t been touched in thirty years. When a DuraFlex fireplace acts up, you don’t need someone who’s just familiar with the brand. You need someone who knows how those components actually fail in Cobb County’s climate and what to do about it.
Every repair we do carries the 365-Day Done Right Promise: a written guarantee, and if it fails within a year, we return free and fix it. That’s not a promotion – it’s company policy, on every single job, since day one. Our techs are background-checked and uniformed, and your arrival window is actually tracked, so you’re not burning a whole afternoon waiting on a phone call. The Relay Visibility Guarantee covers every visit: live arrival tracking, before-and-after photo documentation, and a digital invoice you can pay from a link. We also work with HeatShield ceramic repair compound and Gelco chimney systems, so if your fireplace issue turns out to be a liner or masonry problem, we’re already equipped to handle it without handing you off to someone else. Calls are answered by a live person 24/7 – not an answering service that promises a callback.
FAQs
No – as long as the repair is done with parts that meet DuraFlex’s specifications and the venting isn’t altered in a way that violates the installation manual. We’re an independent DuraFlex service provider, not a manufacturer rep, and we install OEM DuraFlex components when they’re needed. If there’s an active warranty claim, we’ll help you understand what’s covered and what isn’t before you spend a dollar.
The decision comes down to two things: the condition of the venting and the cost of the gas components that are failing. If your direct-vent pipe is rusted through or improperly installed, replacement is often cheaper than trying to patch a system that’s fighting itself. But if you’ve got a bad thermocouple or a tired pilot assembly and the venting is sound, repair usually makes sense – those are straightforward fixes. We’ll send you photos and a written diagnosis so you can actually see what you’re deciding on.
Most common DuraFlex parts – thermocouples, gaskets, storm collars, termination caps, pilot assemblies – are in stock with our local suppliers, and we can typically complete the repair in one visit. Less common components, like a full replacement section of DirectVent Pro pipe or a FasNSeal adapter, take three to five business days. We’ll tell you when the part arrives, and you’ll get a tracked arrival window for the return visit.
That’s usually a venting problem, not a gas supply problem. When the direct-vent pipe can’t get enough intake air or can’t exhaust properly, the oxygen sensor trips and shuts the unit down as a safety measure. A failed gasket at the wall thimble or termination cap, a sagging flex liner that’s pooled with condensate, or a blocked vent screen are the three most common causes we find in Marietta. We’ll diagnose exactly which one you have and send you the photos before we recommend a fix. Call (762) 249-4619 and we’ll get it sorted.
Yes. If you own a home with an existing DuraFlex system and you just want to know what condition the venting is in – before fire season or after a storm – we do a full camera inspection of the entire vent run from fireplace to termination, and you get a written report with photos. It costs $95 – $175 depending on how long the run is and how accessible the chase is. That’s a lot cheaper than finding out there’s a problem when your fireplace won’t light on the first chilly night in November.
Written by Cory Mitchell, Owner, Hadley Chimney Marietta at Hadley Chimney Marietta, serving Marietta and nearby areas.