The failure mode is ordinary. The phone rings during the first cold week, when a cracked tile becomes a rush before anyone lights the stove, nobody answers, and the liner on the truck is short and the flue stays open another week.
Audrey answers and writes flue height, tile size, and the appliance vent diameter before talking about a clock time. The Liner feet turns those counts into feet of liner so the company sees a size, not a vague "can you come look."
Then one company is offered the note. A local crew drops the liner. Audrey does not light the appliance. If the window cannot be met, the caller hears the next real opening, not a promise that keeps the board pretty.
The note is the product. A callback that skips flue height, tile size, and the appliance vent diameter creates the second angry call.
