CleaverBrooks CBT - Page 88

Maintenance
5-20
750-382
CBT
Check if blower is turn-
ing when not on.
Resolve draft condi-
tion (e.g. adjust stack
damper) to near neu-
tral (0" w.c.)
K.2. Blower running
when boiler is off
Check Firing rate and
Fan speed on Falcon
status screen
If Firing rate indicates
0 or low RPM and Fan
speed is at a high
RPM, inspect/secure
blower signal cable
connections at both
ends. A disconnected
blower signal cable will
result in the blower
running at full speed.
At Operation screen,
check Modulation Fir-
ing rate setting
If set to "Manual in
Run & Standby", set to
"Automatic" or "Man-
ual in Run"
K.3. Combustion Air
Proving switch (CAPS)
failure
Check switch connec-
tions and proper func-
tion of air switch.
Correct/secure connec-
tions. Clear lockout
and restart. If CAPS
not functioning,
replace air switch.
Light-off problems L. Lockout 109 Igni-
tion Failure
L.1. Gas supply - is
pressure too low at
boiler gas valve inlet
during trial for ignition
Check for flame signal
on boiler status screen
(DC Volts)
Increase gas supply
pressure to boiler room
(refer to manual's com-
missioning section for
minimum gas supply
pressure requirement
and recommended gas
line sizing)
Increase gas supply
pipe size
Adjust setting of boiler
gas regulator
Clear Lockout and try
again
L.2. Manual gas valve
located between gas
valve and venturi
closed
Check position of man-
ual shut-off valves
Open Manual Gas
Valve
L.3. Gas safety shut-off
valve not opening
Check gas valve indica-
tor LED's during trial
for ignition
If LED(s) not energiz-
ing, secure gas valve
wiring connections.
Refer to boiler wiring
diagram. Ensure DIN
connector is secured to
gas valve.
Problem Display Message Possible Cause/Symp-
tom
Diagnostic Check Corrective Measures