Weil-McLain SlimFit Manual page 108

SlimFit
™
commercial condensing gas
Troubleshooting
Figure 103 Troubleshooting suggestions for SlimFit boilers
Display Condition
Inlet/outlet Occurs when a return
inversion limit water temperature
is greater than the
corresponding supply
temperature for 5
minutes during run.
Inlet Sensor fault; Occurs when a
Outlet Sensor temperature sensor
fault; header has electrically shorted
Sensor fault; Stack or has become
Sensor fault; disconnected.
Outdoor sensor
fault
Occurs when dual
temperature sensors
values have spread by
more that 6ºF
Stack Limit Occurs when flue
temperature sensor
exceeds 216ºF
Outlet high Limit Boiler outlet
temperature sensor
reached 200ºF
Flame detected out Occurs when flame is
of sequence detected when there
should be no flame
Flame lost early in
Flame lost after
run or Flame lost ignition
in run
108
-
fired water boiler
(continued)
(continued)
Diagnostics
Manual reset required.
Automatically resets if sensors begin
reading temperatures.
Automatically resets when sensors are
within 6ºF.
Automatically resets after 5 minute delay.
Reset with manual reset on display
Reset with manual reset on display
Automatically resets after 5 minute delay.
— Boiler Manual
Corrective actions
• Verify proper flow direction of the boiler pump. This pump
should be installed to push water through the boiler's return
pipe as shown in Figure x on page x.
Verify proper placement of system sensors for single or multiple
boiler systems. System sensors should be on system piping not
on the boiler loop.
System sensors may need to be located further away from boiler
loop connection to the system if proximity to the boiler loop is
causing sensors to be heated inaccurately.
• Check all the temperature readings of the boiler on the Boiler
Icon-Diagnostics-Analog I/O and determine if any sensors are
currently displayed as SHORT or OPEN.
• Determine which sensors are suspect and measure their resis-
tance value and compare it to the values shown in Figure 102,
page 104. If the resistance values are incorrect, replace the
temperature sensor. Refer to repair parts section for proper part
number.
• OUTDOOR/HEADER are the optional outdoor air temperature
and system water temperature sensors. If these are not being
used they will always be shown as OPEN. This is normal unless
the sensors were installed.
• Check wire harness for loose connections and pin engagement
at sensor connection, chassis mount connection through sheet
metal cabinet, and Sola Control module. Unplug connection at
sensor and at Sola control and check continuity between ends.
• If problem persists after checking items above replace Sola
Control. Refer to repair parts section for kit number.
• Follow procedure for above for SHORT and OPEN sensor condi-
tions to properly diagnose sensor. If measured resistance values
of sensors convert to temperatures separated by more than 6ºF
replace the sensor.
• Follow procedure for above for SHORT and OPEN sensor condi-
tions to properly diagnose sensor. In addition inspect heat
exchanger combustion chamber and flue ways for abnormal
wear or buildup.
• Inspect vent system for abnormal wear or damage.
• Contact Weil-McLain Technical Support.
• Verify all isolation valves are open and pumps are programmed
into the Sola Control properly. Refer to the Sola Control Setup
section to configure these properly for the system.
• 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.
• Verify FLAME value on the (Boiler Icon) screen quickly goes to
zero when the gas valve closes.
• Check for flame at burner via flame current with burner off. Turn
boiler off and watch flame through observation port. If flame
continues after shutdown replace gas valve and venturi.
• Check gas supply pressure
Inspect flame sense electrode and wiring
Part number 550-100-116/0713