Weil-McLain SlimFit 2 Series Manual page 96

™
SlimFit
COMMERCIAL CONDENSING GAS
Troubleshooting
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
LIMIT
setting (no higher than 200° F).
Occurs if flame is detected
FLAME FAULT
when there should be no
flame.
BLOWER FAULT Blower unable to reach
required speed or does not
reach 0 RPM when turned off.
96
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FIRED WATER BOILER
(continued)
(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.
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Boiler Manual Series 2
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.
Part number 550-100-162/0815