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IV. SOOT IN FLUEWAYS OR IN TUBES, OR
NOXIOUS FUMES INDICATIVE OF BAD
COMBUSTION
Possible Cause What To Do
A. Combustion air supply to heater
A. Check air supply opening. Look
room is inadequate.
for debris in screen or louvre
which covers combustion air
opening, or for material blocking
the opening.
B. Stack or vent is blocked or
B. Look for blocked stack and
restrictive.
excessive number of elbows in
stack or excessive length of
horizontal runs.
C. Severe down draft is causing
C. Check for (1) proper vent cap on
spillage of flue products into room.
stack; (2) adequate height of
stack above roof; (3) equipment
exhausting air from inside of
building; and (4) proper
installation of draft diverter.
D. Gas pressure to burners is
D. Check gas pressure with
excessive.
nanometer, and adjust with
heater firing at full rate.
E. Heater not fitted for the fuel being
E. See nameplate for correct fuel.
supplied.
F. Heater installed at high altitude
F. Installations at altitudes in excess
without proper derating.
of 2000 ft. above sea level are
subject to jurisdiction of the local
inspection authorities.
V. WATER DRIPPING
IN FIREBOX
Possible Cause What To Do
Tub in heat exchanger has
A tube failure is almost always
overheated and ruptured.
caused by (a) scale formation in the
tube or (b) inadequate water flow
through the boiler.
