Quick answer: A DIY chimney liner kit costs $300 to $800 for a standard installation. Professional chimney relining runs $1,500 to $5,000. The difference is labor: the materials are the same. If you have a straight masonry chimney and basic DIY skills, a kit saves you $1,000 to $4,000.

For most wood stove and coal stove installations, yes, a chimney liner should be insulated. Insulating the liner keeps the flue gases hot, which gives a stronger draft and far less creosote, and it is often required to meet the liner's safety listing.
For gas, oil and pellet appliances it is usually not needed.

Relining a chimney is one of the most common ways to make an old masonry chimney safe again for a wood stove, insert, or other appliance. 

But relining is not a free-for-all. In the United States it is governed by national safety standards, the liner manufacturer's own listing, and your local building code.

Match the pipe to your wood stove's flue collar, which is 6 inches on most modern stoves and 8 inches on larger or older ones. Never size up to "help the draft" (a wider pipe actually weakens it), and never go smaller than the collar.

 Go through the roof when you have a clear vertical path above the stove, because a straight run gives the strongest draft. Go through the wall when the ceiling is cathedral or vaulted, the attic is blocked, or cutting the roof is off the table. Both are equally safe with Class A pipe at 2-inch clearance and the 3-2-10 height rule.

Flue-Pipes.com is the best Selkirk SuperPro alternative. Same UL 103 HT listed Class A chimney pipe — up to 54% lower cost, sold direct with no distributor markup. Every order includes a limited lifetime warranty, 14-day guaranteed returns, and a lowest price guarantee.

Same build quality. Fully listed and certified. Up to 54% less than DuraPlus pricing — backed by a lifetime warranty, 14-day returns, and a lowest price guarantee.

Flue-Pipes.com is the best DuraTech alternative. Same UL 103 HT listed Class A chimney pipe — up to 35% lower than Duratech, sold direct with no distributor markup. Every order includes a limited lifetime warranty, 14-day guaranteed returns, and a lowest price guarantee.

The short answer: pellet stoves use a dedicated pellet vent system, called Type L vent or PL vent, listed to UL 641. It's a smaller diameter (typically 3 or 4 inches) and rated for the lower flue gas temperatures pellet stoves produce. 

The short answer: if you're installing a wood stove or fireplace in a U.S. home that doesn't have an existing masonry chimney, Class A insulated chimney pipe is the system you need.Class A pipe is double-walled, factory-built, insulated, and certified to UL 103 HT for solid fuel appliances.