Cleaver-Brooks CBH 40 - CHAPTER 6 TROUBLE SHOOTING; A. BURNER DOES NOT START; B. NO IGNITION

CHAPTER 6
TROUBLES
OOTING
A. f§URNER DOES NOT START
B. NO IGNITION
C. GAS PilOT FlAME, BUT NO MAIN FlAME
D. lOW FIRE FlAME, BUT NO HIGH FIRE FlAME
E. lOSS OF FlAME
F. DAMPER MOTOR
This section assumes that the unit has been
properly installed and adjusted and that it has
been running for some time prior to the trouble
listed in the heading of each section. It is further
assumed that the operator has become thoroughly
familiar with both burner and manual by this
time. The points under each heading are set down
briefly as possible causes, suggestions or clues to
simplify locating the source of trouble. Methods of
correcting the trouble, once it has been identified,
may be found elsewhere in this manual.
If the burner will not start, or operate properly,
refer to this trouble shooting section and to the
programming relay bulletin for assistance in pin-
pointing problems that may not be readily ap-
parent. Familiarity with the programmer and
other controls in the system may be obtained by
studying the contents of this manual and the
bulletin. Knowledge of the system and its controls
will make troubleshooting much easier. Costly
down time or delays can be prevented by
systematic checks of the actual operation against
the normal sequence to determine the stage at
which performance deviates from normal. Follow-
ing a routine may possibly eliminate overlooking
an obvious condition, often one that is relatively
simple to correct.
If an obvious condition is not apparent, check the
continuity of the circuits with a voltmeter or test
lamp. Each circuit can be checked and the fault
isolated and corrected. Most circuitry checking can
be done between appropriate terminals on the ter-
minal boards in the control cabinet or the entrance
box. Refer to the schematic Wiring Diagram for
terminal identification.
A. BURNER DOES NOT START
1. Main disconnect switch open.
2. Blown fuses, tripped overloads, loose electrical
connections.
3. Combustion control safety switch requires re-
setting
a) Refer to manufacturer's bulletin
b) Check for power between terminals Ll and
L2 (terminal board 4 and· 5)
c)
If relay lK pulls in, but the blower motor
does not start, check for power at pro-
grammer terminal 8
d) Check that appropriate relay contacts are
closed (see programmer bulletin)
4. Limit circuit not completed - no power to pro-
grammer terminal 3
a) Pressure or temperature is above setting of
operating control
b) Water below required level
1) Check manual reset button, if pro-
vided, on low water control
c) Fuel pressure must be within settings of low
pressure and high pressure switches
5. Motor defective.
6.
If burner starts, but shuts down after a few
seconds check the air proving switch circuit.
B. NO IGNITION
1. Lack of spark
a) Electrode grounded or porcelain cracked
b) Improper electrode setting
c) Loose terminal or ignition cable; cable
shorted
d) Inoperative ignition transformer
e) Check appropriate program relay contacts
2. Spark but no flame
a) Lack of fuel - no gas pressure, closed
valve, empty tank, broken line,etc.
b) Inoperative pilot solenoid or low fire oil
valve
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