Weil-McLain SlimFit Manual page 109

SlimFit
™
commercial condensing gas
Troubleshooting
Figure 103 Troubleshooting suggestions for SlimFit boilers
Display Condition
Light off rate Blower unable to
proving failed; reach required speed
Purge rate proving or does not reach 0
failed; Fan speed RPM when turned off.
failed during
prepurge; Fan
Speed failed
during preignition;
Fan speed failed
during ignition;
Fan Speed failed
during run;
Fan movement
detected during
standby
Ignition Failed Boiler went through 2
ignition attempts and
never detected flame
A fault has occurred in
the control hardware
Internal Fault
ILk OFF (Flue Flue pressure switch is
Pressure) opened during run
ILk OFF (Block Block temperature
Temperature) switch reached 203ºF
Part number 550-100-116/0713
-
fired water boiler
(continued)
(continued)
Diagnostics
Requires a manual reset.
Requires a manual reset.
Requires a manual reset.
Requires manual reset.
Requires manual reset
— Boiler Manual
Corrective actions
• Check wire harness for loose connections and pin engagement
at blower connections, chassis mount connection through sheet
metal cabinet, and Sola module. Unplug connection at sensor
and at Sola and check continuity between ends. Blower is con-
nected to both low voltage and line voltage harness.
• Check FAN Boiler Icon-Diagnostics-Analog I/O screen with boiler
in standby mode and blower not running. If BLOWER SPEED is
not 0 RPM then replace blower.
• If blower does not rotate during ignition sequence check for
120V power at blower connection. If 120Vac power at blower
motor and it doesn't start replace blower. Check power at
Blower relay. If 120Vac is not present at Relay when boiler is
powered replace Relay. Refer to repair parts section.
• Fouled, worn, bent, or faulty igniter or flame sense rod.
Fouled igniters and flame sensors can be cleaned for additional
use with fine grit sand paper or steel wool.
Worn or badly fouled igniters and flame sense rods should be
replaced with the proper repair part.
Igniter rods should be parallel with a 3.0mm (0.118in) spark gap.
• Dirty burner and/or heat exchanger will cause high back
pressure and poor ignition. Follow procedure in maintenance
section of this manual to clean burner and heat exchanger using
flue cleaning tool and rinse method.
• Visual inspection of flue ways will often will not be able to
diagnose condition.
• Check combustion settings on high and low fire and adjust per
setup instructions if necessary.
• Check incoming gas pressure with boiler off, at high fire, and at
low fire. Adjust within limits on rating label.
• Verify high altitude settings have been changed for installations
5,500 ft above sea level.
• Check ignition cable resistance. Should measure 1000 Ohms
(+/- 50 Ohms)
• Check continuity of flame sense cable.
• Check ignition transformer is plugged in. If no spark present dur-
ing ignition replace spark transformer
• Check for flue pipe and intake pipe restrictions or blockage
• Check burner fasteners and gaskets
• Check venturi gaskets
• Check condensate trap for blockage allowing condensate to
accumulate inside heat exchanger
• Reset control, If fault returns replace Sola control
• Check for flue pipe and intake pipe restrictions or blockage
• Check continuity of flue pressure switch and flue pressure switch
wiring
• Verify water piping is installed correctly using primary/secondary
connection to the boiler loop. Verify that piping methods and
sizes comply with the instructions in this manual.
• Verify proper pump sizing for boiler size and system require-
ments.
• Verify boiler pump is energized
• See message displayed Inlet sensor fault or outlet sensor fault
and follow procedure for loose connections.
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