The right flue liner depends on your appliance, chimney dimensions, fuel, and local requirements—not just the phrase “Class 1.” The products below include flexible and rigid liners for masonry chimneys, plus one Class-A chimney pipe that is a different product category. None of the supplied listings explicitly identifies a product as a “Class 1 flue liner,” so confirm the required classification and appliance compatibility with the manufacturer or a qualified chimney professional before buying.
| Product | Best suited for | Key distinction |
|---|---|---|
| Duraflex Relining | Buyers seeking a 3-inch flexible liner | 35-foot length |
| DuraVent DuraLiner | Masonry chimney relining | Rigid, 6-inch section |
| FireSafe Flexible Kit | Buyers wanting a flexible liner kit | 316 stainless steel; 15 feet |
| AllFuel HST Pipe | Buyers needing a compatible Class-A pipe component | Not a masonry chimney liner |
| Rockford Flexible Kit | DIY masonry chimney relining | 316 stainless steel; 25 feet |
Duraflex Relining 3-Inch by 35-Foot
This Duraflex relining product is a flexible liner option with a 3-inch diameter and 35-foot length. The listed feature describes the manufacturer’s work across HVAC, hearth, and industrial venting applications; it does not specify the liner’s material, fuel compatibility, or a Class 1 designation.
Best for: Buyers whose measured liner requirements call for a 3-inch, 35-foot relining product and who can verify its suitability for their appliance. It was selected because its stated dimensions distinguish it from the 6-inch options below.
Limitation: The supplied listing details do not confirm included installation parts or a specific approval for a Class 1 system. Check those details before purchase.
DuraVent DuraLiner 6-Inch Rigid Section
The DuraLiner is a 6-inch-diameter, 24-inch rigid liner section made from aluminized steel. Its listed use is relining a masonry chimney with zero clearance. That stated application makes it the clearest choice here for a buyer seeking a rigid section specifically for masonry chimney relining.
Best for: Buyers planning a rigid DuraLiner installation who need a 6-inch section and have confirmed the chimney and appliance requirements. Choose this over a flexible kit if the specified system calls for rigid components.
Limitation: This is a 24-inch section, not a complete liner kit. Confirm the required number of sections and system components with the product documentation.
FireSafe 6-Inch Flexible Liner Kit
This 6-inch-by-15-foot flexible kit is described as a 316 stainless steel liner with 7-ply seams and 10 corrugations. The listed kit includes a 13-by-13-inch top plate with rain cap and an appliance connector for vertical hookups. Its stated uses include fireplace inserts and wood stoves.
Best for: Buyers looking for a shorter, flexible 6-inch kit with several installation components listed together. It offers a more complete starting point than a liner-only section, but verify that the included parts suit the actual installation.
Limitation: The listing does not establish that this kit meets every Class 1 requirement or fits every appliance. Confirm fuel type, diameter, and applicable local rules.
AllFuel HST 6-Inch Class-A Chimney Pipe
This 48-inch component is Class-A double-wall chimney pipe, not a flexible or rigid masonry chimney liner. It has 304 stainless steel inner and outer walls, laser-welded seams, and ceramic-fiber insulation. The listing states a 2-inch clearance to combustibles and compatibility with AllFuel HST Class-A pipe.
Best for: Buyers comparing chimney-system components who specifically need a compatible AllFuel HST Class-A pipe section. It is included to clarify a commonly confused product category.
Limitation: Do not treat it as a substitute for a liner. The listing says it cannot connect to other brands of Class-A chimney pipe.
Rockford 6-Inch Flexible Liner Kit
Rockford’s 6-inch-by-25-foot kit uses 316 stainless steel. The listing includes DIY installation instructions and states that the flexible liner is intended only for installation inside a masonry chimney. It also identifies UL 1777 listing in the United States and ULCS635 in Canada.
Best for: Buyers relining a masonry chimney who need a longer flexible liner and want installation instructions included. Its stated masonry-only scope helps distinguish it from Class-A chimney pipe.
Limitation: The listed restriction matters: do not select this flexible liner for an installation outside a masonry chimney. Verify that 25 feet is the correct length.
Buying Guide: How to Choose a Flue Liner
What does “Class 1” mean for your installation?
Product terminology can vary by country, appliance, and venting system. The supplied listings do not identify these products as Class 1 liners. Check the appliance instructions and local code for the exact classification, liner type, and required listing. Ask the manufacturer or a qualified installer to confirm any uncertainty.
Should you choose flexible or rigid?
Flexible liners can suit routes where a flexible product is specified, while rigid sections may be appropriate in systems designed for rigid components. Compare the chimney’s route and dimensions with the product instructions. Do not assume that flexible and rigid parts can be mixed.
How do diameter and length affect selection?
Match the liner diameter and total length to the appliance and chimney specifications. The products here range from 3-inch to 6-inch diameters and vary in length. Do not choose a size based only on the existing chimney opening; confirm the appliance’s required flue size.
Is a chimney liner the same as Class-A pipe?
No. The AllFuel listing describes insulated Class-A chimney pipe and restricts it to its own compatible pipe system. The flexible kits and DuraLiner section are described as chimney liner products. Confirm the component category before ordering.
Frequently Asked Questions
Are these products confirmed as Class 1 flue liners?
No. The provided product information does not explicitly identify any of the five as a Class 1 flue liner. Verify classification with the manufacturer and applicable installation requirements.
Which option is specifically described for masonry chimney relining?
The DuraVent DuraLiner is listed for relining masonry chimneys. The Rockford flexible liner also states that it is for installation inside a masonry chimney.
Which flexible kit includes a top plate and rain cap?
The FireSafe kit listing includes a 13-by-13-inch top plate with a rain cap and an appliance connector.
Can the AllFuel pipe replace a liner?
No. It is listed as Class-A double-wall chimney pipe, a different product category from a chimney liner.
What should I check before buying?
Confirm appliance fuel and instructions, required liner classification, diameter, length, chimney type, included parts, and local code requirements.