CoalUserWannabe wrote:If it is a stainless steel rated for coal, it will last a lot longer than you think, and in that case you may want to leave it there, it may give yo a better seal and a better draft, the hot air column rising is what produces draft, and sometimes it's hard to heat that air if the chimney is too cold with big mass. Lucky for you a stoker won't have the trouble since it has its own combustion blower, and does not rely on draft to start the coal.
stainless "rated for coal" ? that would be 316 or 316ti which won't last long. I've seen 316/ti fail with oil, I've seen them fail with coal, and there was a 316ti liner that failed in about three years with anthracite coal. After tearing down stainless stacks that appeared (from the exterior) to be in good shape, the interior was pinholed and rotted. I tore two out in the last year like this, one with oil, and one with only a few years on coal.
Stainless doesn't last with coal and is a poor choice. If someone has actually inspected
the inside of their stainless stack or liner after 5+ years of coal use and had little or no damage they would be the exception, not the rule.
remove the liner and don't look back. be sure that your stack is high enough for your home to have proper operation especially if it's a large exterior stack - ideally 3' higher than the peak regardless of where it exits, remember the 10/2 rule is a minimum requirement, NOT a recommendation!