DuraFlex Flue Liner Replacement Nationwide

DuraFlex Flue Liner Replacement: The Greenwich Owner’s Guide

A DuraFlex flue liner replacement in Greenwich typically runs $2,400 to $4,800 installed, depending on flue height and whether the old liner comes out clean or fights you on the way up. We stock DuraFlex-compatible 316L and AL29-4C stainless liner kits on the truck, so most replacements are done in a single visit. Most homeowners find out their DuraFlex liner needs replacing the hard way: a sweep’s camera finds a seam separation or corrosion pinholes during a Level 2 inspection, or the water heater starts throwing a backdraft code and nobody can figure out why until we put a camera down the flue.

Call (516) 399-5497

Which DuraFlex Models This Applies To

The DuraFlex product line splits into two families: the 316L alloy liners for wood and pellet stoves, and the AL29-4C high-temp alloy for gas and oil appliances. They are not interchangeable. If your liner feeds a gas furnace and someone installs a 316L replacement, you’ll get corrosion within three to five years from acidic condensate eating the alloy. The original installer should have left a label on the liner’s top plate or inside the appliance connector; if not, we measure the inner diameter and check the appliance’s BTU rating against DuraFlex’s sizing chart (typically 4″ for most inserts, 5″ or 6″ for larger fireplaces, and up to 8″ for open hearth chimney liners). As an independent service provider, we’re not affiliated with DuraFlex, but we source directly through our buying network, which keeps the markup honest compared to dealer-channel pricing.

Signs Your DuraFlex Flue Liner Replacement Is Failing

• Flue gas smell in the house, especially on humid days. This usually means a seam has separated or the liner has developed pinholes. Condensate carries combustion byproducts through the gap and into your living space.
• White or brown staining on the chimney exterior. In Greenwich, our freeze-thaw cycles accelerate this: moisture gets between the liner and masonry, freezes, and forces its way out through the brick face on warm days.
• Liner pieces showing up in the firebox or cleanout. Not common with stainless, but if the liner predates 2008 and was installed without proper insulation, metal fatigue plus CT coastal humidity can cause it.
• The appliance keeps tripping a rollout or backdraft sensor. This tells you the flue is partially blocked or the liner isn’t drawing properly. Have it camera-scanned before you keep resetting it.
• A camera inspection shows rust, scaling, or seam gaps at the joints. This is the only way to actually know. Everything else is a guess. The camera doesn’t guess. Neither do we.

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After

Replacement Cost & What’s Included

For a typical single-story Greenwich colonial with a 20-25 foot flue, a DuraFlex-compatible 316L liner replacement runs $2,400 to $3,200. An AL29-4C liner for a gas appliance runs $2,900 to $3,800. Add $400 to $600 if the old liner is fused to the flue wall and needs cutting out. Every quote is written before any work starts, per Haven Standard Clause 1. The price includes removal of the failed liner, the new liner (sized to your exact flue diameter, not “close enough”), insulation wrap where required by code, top plate and rain cap, and a full camera-scan photo record on completion. The labor carries our 365-Day Done Right Promise: if it’s not right, we fix it.

What’s included line-by-line:

• Failed liner removal and disposal
• New DuraFlex-compatible liner (316L or AL29-4C, sized to your flue)
• Insulation wrap (required by NFPA 211 for exterior chimneys in our climate)
• Top plate, rain cap, and appliance connector
• Camera-scan verification and full photo record
• 365-Day Done Right Promise, written and signed

DIY or Call Us?

You can safely check the parts you can see without getting on a ladder: the cleanout door at the base of the chimney, the firebox area, and the connector pipe. If you find rust flakes, a powdery residue, or water staining, get a camera inspection. Replacing the liner means working from the top of the chimney or from the appliance connection below: that means ladders or roof work, cutting stainless steel, and dropping a 30-pound coiled liner down a masonry flue without tearing it on a cracked tile. That last part is where DIY jobs fail most often. A torn liner after install won’t show itself until the next backdraft code. If you’re not set up for this, or if you have any doubt about the condition of the flue tiles, call (516) 399-5497 and we’ll put a camera down first.

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