Putting out a chimney fire ??'s..

[Al_Smith]

I've never had one but I have a 9 inch clay lined flue  that would creosote .I stuffed a 7" welded seam 22 gauge single wall stainless steel liner in it and filled the voids with fiber glass .That fixed it .I went to a builders supply for the pipe rather than spend a kings ransom at a so called stove shop .Total length 14 feet. I brush it once a year .
The job took me about 4 days and it took some creativity to move a 700 pound insert out of the way and plate the entire top of existing fire place .Then move that heavy pot licker back in place .That's a fire brick lined plate steel insert made for the long  haul .Glass front Lopi circa early 80's .Rated at 55,000 BTU . 

[firefighter ontheside]

Tom previously mentioned that we use dry chem "bombs" which is essentially a bag full of dry chemical extinguishing agent and we drop it down the chimney from the top.  The first thing we always do though is to remove all burning material from the fire box.  In many cases, that alone will make the fire go out since there is no more heat coming up from the box.  We will also put a positive pressure fan at the front door of the home with damper open and then shoot a dry chem extinguisher into the fire box.  The air being forced up the flu will take the agent up the flu.  Then we shut the damper and fire box door to stop the flow of air.  We only use water if it appears that the fire has extended outside of the flu and into other building components.  Many flues that have had frequent flu fires have cracked liners which is a path for the fire to escape the flu.

[Crusarius]

I remember one chimney fire we went to that had a clay block chimney. Over the years the creosote had worked its way in between the clay blocks. When the creosote lit it was the normal raging rocket when we arrived. After we thought we had the fire out we continued seeing signs of fire. The creosote going between the clay liner was burning and it extended into the house. We had to remove half of the house to get the fire to stop spreading through the floor joists and walls.

was not a good day. a simple chimney fire turned into full on structure fire and about 12 hours of work.

[SwampDonkey]

shoot a dry chem extinguisher into the fire box.  The air being forced up the flu will take the agent up the flu.  Then we shut the damper and fire box door to stop the flow of air. 

That's how I put out one years ago, over and done with.

[Al_Smith]

A clay liner worked well for a conventional furnace or a fire place .However with higher efficiency gas furnaces  even before the ones today the vapor of combustion would wick right through them causing all kinds of problems .Those you can get by with an aluminum liner .
Not so on something like an insert .Those take stainless steel .As I've said my single wall heavy stainless cured the possibility  and I think I might have had $150 or so in it .I had to buy a heavy duty pop rivet tool to compress the pop rivets .They certainly are not like regular rivets .