Weil-McLain SlimFit 2 Series Manual page 99

SlimFit ® Series 2
Troubleshooting
Figure 92 Troubleshooting suggestions for SlimFit boilers
Display Condition
Occurs if manual or automatic
LIMIT OPEN
reset limit opens.
Boiler temperature sensor
HIGH TEMP
reached High Temp Limit setting
LIMIT
(no higher than 200° F).
Occurs if flame is detected when
FLAME FAULT
there should be no flame.
Blower unable to reach required
BLOWER
FAULT speed or does not reach 0 RPM
when turned off.
Part number 550-100-561/0224
commercial condensing gas
(continued)
Diagnostics
Automatic external limit will reset
2½ minutes after external limit
device closes.
Manual limit fault must be reset
by choosing Manual Reset on the
display.
Reset using manual reset screen
on display.
Reset using manual reset screen
on display.
Reset using manual reset screen
on display; Control will check again
after 1 hour and will automatically
restart if condition is corrected.
- — Boiler Manual
fired water boiler
(continued)
Corrective Action(s)
Is there an external safety device connected? If yes, trouble shoot the external
limit to determine and correct the cause that opened the limit. Also check for
loose wiring connections.
Remove the top right Control tray cover and inspect the connector.
Ensure a jumper is installed across the MAN LIMIT terminals if not using a
manual reset external limit.
Ensure a jumper is installed across the AUTO LIMIT terminals if not using a
automatic reset external limit.
Verify that high limit setting is at least 10° F above the maximum target
temperature plus the off differential.
Verify all isolation valves are open and circulators are programmed into the
control properly.
The boiler circulator output and System Pump/Aux. output can be configured to
turn on or off with each priority. Refer to the Control Setup section to configure
these properly for the system.
Verify water pipe is installed correctly per instructions in this manual.
Verify proper circulator sizing for boiler size and system requirements.
See message displayed TEMPERATURE SENSOR and follow procedure for
loose connections.
Burner may be operating too hot due to incorrect combustion. Inspect flame and
conduct combustion test.
Force boiler into high fire. Check flue gases with combustion analyzer and
correct using the maintenance and startup procedure in this manual.
Verify FLAME SIGNAL value quickly goes to zero on the DIAGNOSTICS -
INPUTS screen 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 shut down
replace gas valve.
Check wire harness for loose connections and pin engagement at blower
connections, chassis mount connection through control housing, and control.
Unplug connection at blower and at control and check continuity between ends.
Blower is connected to both low voltage and line voltage harness.
Check Diagnostics - Inputs 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 120 VAC power at blower motor and it doesn't start
replace blower. Check power at control. If 120VAC is not present at control
when boiler is powered replace Control. Refer to repair parts section.
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