CleaverBrooks CBT - Page 89

750-382
CBT
5-21
Troubleshooting
L.4. Gas supply restric-
tion -- improperly sized
high pressure regulator,
gas pipe size to small,
too many elbows, high
lockup pressure, no
gas pressure relief (>1
psig supply pressure),
insufficient gas vol-
ume supply to boiler
room,…
Monitor gas supply
pressure at boiler gas
valve inlet during trial
for ignition and modu-
lation -- note gas pres-
sure at low fire and
high fire rates.
If significant fluctations
in gas pressure (e.g. 5"
to 10" of droop) are
observed, identify gas
supply restriction and
correct condition(s).
L.5. Multiple appli-
ances sharing an insuf-
ficiently sized gas
supply header
Note gas supply pres-
sure when all appli-
ances are firing at
rated capacity.
If gas supply pressure
drops below minimum
requirement, correct
gas supply header pipe
sizing.
L.6. Ignitor weak or not
sparking - check
burner sight port for
visual spark indication
during trial for ignition
Check for flame signal
on boiler status screen
(DC Volts) during trial
for ignition.
Check ignition cables
for secure connection
to sparking electrodes -
replace if connection is
loose or if insulation is
brittle and/or charred
Check for wiring to
ignition transformer;
check ground of trans-
former
Secure wiring and
ground connection to
ignition transformer
Check dual sparking
electrodes condition,
gap, and condition of
insulators
Replace ignition cables
Clear Lockout and try
again
Check for power
between terminals 2 &
4 in control panel
during trial for ignition.
If power present,
replace ignition trans-
former; if no, check
wiring from Falcon
control to ignition
transformer and
secure.
Clear Lockout and try
again
L.7. Combustion Air
restriction - dirty/
clogged air filter
Check for flame signal inspect/clean air filter
L.8. Blocked air intake Check for flame signal inspect air intake/
remove blockage
L.9. Blocked flue/
exhaust
Check for flame signal inspect flue/remove
blockage
Problem Display Message Possible Cause/Symp-
tom
Diagnostic Check Corrective Measures