Weil-McLain SlimFit 2 Series Manual page 101

SlimFit ® Series 2
Troubleshooting
Figure 92 Troubleshooting suggestions for SlimFit boilers
Display
Condition
MINIMUM Min air flow switch is open when
AIR FLOW it should be closed, or closed
SWITCH
when it should be open.
FAULT
Expansion Control Board
HW FAULT
EXPANSION hardware has failed.
BRD
GV FAULT Gas valve output of the
EXPANSION Expansion module.
BRD
EXP BOARD Expansion Control Board
COM FAULT communication fault.
Hardware Fault Occurs when micro-controllers on
main board have a RAM or ROM
error, or communication is cut off.
Hardware The control has detected a
problem with its gas valve output
Fault 1,2,3,4
circuit.
Closure Closure switch connections on
P7 Pins 2 and 3 are open for
Switch Fault
more than 4 minutes
Outdoor temperature sensor
OUTDOOR
short or OPEN.
SENSOR
ERROR
Occurs if flue temperature
Flue Temp Too
sensor exceeds 210°F (Warning)
High
or 220°F (Lockout).
Part number 550-100-561/0224
commercial condensing gas
(continued)
Diagnostics
Switch should close when the
blower passes enough air.
Manual reset is required.
Expansion Control Board has
detected an issue with it's
hardware and has locked out.
Requires a manual reset.
Expansion Control Board has
detected an issue with the gas
valve circuit. Requires a manual
reset.
Communication has been lost
between the Control and the
Expansion Control Board.
Check for hardware damages.
Auto reset if condition is clear after
lockout, then 1 hour automatic reset
if condition clear, then manual reset
required.
Soft lockout when 4 minute timer
expires. Reset when closure is
made.
Will automatically reset if the
condition clears.
Warning only. Supply Max is
targeted until ODT is restored, if
used for target adjustment.
Automatic reset occurs if
temperature drops below 210°F for
2 ½ minutes.
Manual reset is required if the
temperature rises above 220°F.
Reset using manual reset screen
on display.
- — Boiler Manual
fired water boiler
(continued)
Corrective Action(s)
Check blower is operating correctly.
Check to see if switch is not stuck open/closed.
Check hose connection to switch for disconnect or damaged.
Check wiring connections are firmly connected and not damaged.
Check if Combustion Air Pressure Kit has been installed.
Check sense line connections.
Check electrical wiring.
Check to see if switch is stuck open/closed.
Check boiler size selected in Control against boiler rating label. Correct if
necessary to select the proper boiler size.
Check the wire harnesses between the Control, Expansion module, and gas
valve.
Check the communication wire harness between the two controls.
RAM or ROM errors can be reset with the manual reset option.
If problems persist, replace main board.
Check for physical damages.
Check connections to gas valve and gas pressure.
If problem persists, replace main board.
None – Check jumper on correct pins and secure connection.
Flow switch attached – Check correct pump is on, check wiring to flow switch,
and check switch is closing.
CAD – Check voltage to damper. Check damper is opening.
Determine which sensors are suspect and measure their resistance value and
compare it to the values shown in Figure 90, page 94. If the resistance values
are incorrect replace the temperature sensor. Refer to repair parts section for
proper part number.
Check wire harness for loose connections and pin engagement at sensor
connection, chassis mount connection through control housing, and the control.
Unplug connection at sensor and at control and check continuity between ends.
If problem persists after checking items above, replace control. Refer to repair
parts section for kit number.
Follow procedure above for SHORT and OPEN sensor conditions to properly
diagnose sensor. In addition inspect heat exchanger combustion chamber and
flue-ways for abnormal wear and buildup.
Inspect vent system for abnormal wear or damage.
Contact Weil-McLain Technical Support.
101