Overview
The Forever Flex 3" Stainless Steel Chimney Liner is a flexible liner for relining a masonry chimney, pre-cut at the factory to the length you choose. Pick the alloy and length below. Buy it from StoveSource and pay no sales tax in any state.
This is the liner only. Add the top plate, rain cap and connection hardware listed below.
Which liner do you need?
| Liner | Best for |
|---|---|
| Standard .005" 316Ti | Wood, coal, oil and gas. The everyday choice for most wood stoves and inserts. |
| Heavy-Duty .006" 316Ti | Wood, coal, oil and gas, with a thicker .006" wall for extra durability. |
| AL29-4C | High-efficiency gas and oil appliances that call for AL29-4C venting. |
Lengths
Available in 15, 20, 25, 30, 35, 45 and 50 ft lengths (not every alloy comes in every length). Measure from the top of the chimney crown down to the appliance connection, then add about a foot for trimming.
Complete the install
- Forever Flex 3" rain cap with screen (CSLF3)
- Forever Flex 3" No-Sag 13" x 13" top plate (TPNS3-1313)
- Forever Flex 3" appliance connector (ACLF3)
- Forever Flex 3" tee with 10" take-off (TLF3)
- Forever Flex 3" tee cap (TC3)
- Forever Flex 3" liner coupling (LC3)
Sizes and part numbers
| Liner | Length | Part number |
|---|---|---|
| Standard .005" 316Ti | 15 ft | L5S315 |
| Standard .005" 316Ti | 20 ft | L5S320 |
| Standard .005" 316Ti | 25 ft | L5S325 |
| Standard .005" 316Ti | 30 ft | L5S330 |
| Standard .005" 316Ti | 35 ft | L5S335 |
| Heavy-Duty .006" 316Ti | 15 ft | L6S315 |
| Heavy-Duty .006" 316Ti | 20 ft | L6S320 |
| Heavy-Duty .006" 316Ti | 25 ft | L6S325 |
| Heavy-Duty .006" 316Ti | 30 ft | L6S330 |
| Heavy-Duty .006" 316Ti | 35 ft | L6S335 |
| Heavy-Duty .006" 316Ti | 45 ft | L6S345 |
| Heavy-Duty .006" 316Ti | 50 ft | L6S350 |
| AL29-4C | 20 ft | L29320 |
Sizing tip
Match the liner diameter to your appliance flue collar, and never go smaller than the collar. Many wood stove manuals and building codes require an insulated liner, so check your manual before ordering.
Parts for your liner install
- Top of the chimney: rain cap, Deluxe Top cap and plate, top plates (No-Sag 13x13, No-Sag 13x18 and 18x18, flat, terracotta 8x8 or larger), storm collar and support clamp
- At the appliance: tee and tee cap, appliance connector, quick connector, elbows, offset box and reducers
- Installing it: pulling nose cone, insulation (FlexWrap blanket or Super Wrap kit), liner coupling and mortar collar
See every fitting in chimney liner parts and fittings.
Why buy from StoveSource: Authorized dealer · No Sales Tax · Free shipping over $250 · 1-888-914-0022
Shipping & Returns
Free shipping on orders over $250 · ships in 1–3 business days.
Free shipping on orders over $250 to the continental US; a flat $22.95 shipping fee applies to orders under $250. Accessories and parts ship by parcel carrier (UPS, FedEx, or USPS), typically in 1–3 business days.
Returns. Unused, uninstalled items in original packaging can be returned within 30 days, subject to a 15% restocking fee.
Sold by StoveSource (authorized dealer). Ships directly from the brand's authorized distributor warehouse — see our Authorized Dealer page.