Correct
Incorrect
Faulty draught
because a
fire-place's
door (not in
use) is open
False air because of an
open tube joint
False air
because of a
leaky tube joint
29
Tightening cross section
of the chimney because
the smoke tube is pushed
into the chimney too much
Obstruction because
the smoke tubes are
led as facing each
other
False air because
of open
fire-place door