Weil-McLain SlimFit 2 Series Manual page 98

SlimFit Series 2
®
Troubleshooting
Figure 92 Troubleshooting suggestions for SlimFit boilers
Control Fault Displays, Diagnostics and Suggested Corrective Actions
Display Condition
LOW WTR Occurs if internal low water
CUTOFF OPEN cutoff contacts open.
Boiler Out temperature
SUPPLY 58° F >
has exceeded the Boiler In
RETURN
temperature by more than
58º F.
RETURN > Occurs if a return water
temperature is greater than
SUPPLY
the corresponding supply
temperature by 10º F or
more.
SUPPLY WATER Occurs when the System
Supply temperature goes
TEMPERATURE
above 200º F when the
TOO HIGH
burner is running.
TEMPERATURE Occurs if a temperature
sensor has electrically
SENSOR FAULT
shorted (SHORT) or has
become disconnected
(OPEN).
98
commercial condensing gas
(continued)
Diagnostics
Automatic reset occurs if contacts
are open at least one second, but
less than 5 seconds.
Manual reset of control if contacts
are open longer than 5 seconds.
Automatically resets after 30
second delay when conditions no
longer exist or using manual reset
on display.
Automatically resets when
condition no longer exists.
Automatically resets when Supply
temperature goes below 200º F.
Will automatically reset if the
condition clears.
— Boiler Manual
-
fired water boiler
(continued)
Corrective Action(s)
Check for low water condition in system. Repair system as necessary refer to
piping section of this manual.
If low water condition does not exist, check Diagnostics — Inputs screen to view
status of Low Water Cutoff. If shown as OPEN check wiring between LWCO
and control. If wiring is alright, remove LWCO and Clean probe. If problem still
exist, then replace the LWCO.
Low water cutoff indicator light codes:
GREEN on = Normal operation
GREEN + AMBER on = Service probe soon
RED + AMBER = Control locked out
RED blinking = LWCO component failure
When the service indicator light code occurs, schedule a service
appointment as soon as possible to avoid the boiler shutting down
on low water lockout. To service the probe, shut off all power sup-
plies to the boiler. Close the boiler isolation valves. Then drain
enough water from the boiler to allow removing the low water cutoff.
Inspect the probe. Clean if necessary to remove scale accumula-
tion. Reinstall the low water cutoff and restore boiler to operation.
If the problem persists, replace the low water cutoff probe.
Verify water pipe is installed correctly per instructions in this manual.
Verify proper circulator and speed for boiler size and system requirements.
See message displayed TEMPERATURE SENSOR and follow procedure for
loose connections.
Verify proper flow direction of the boiler circulator.
Verify proper placement of system sensors for single or multiple boiler system.
System sensors should be on system piping not on the boiler loop.
Verify sensors are wired to correct terminal locations.
System sensors may need to be located further away from the boiler loop
connection to the system, if proximity to the boiler loop is causing sensors to be
heated inaccurately.
Verify proper flow direction of the boiler circulator. This circulator must be
installed to push water through the system.
Check all the temperature readings of the boiler on the DIAGNOSTICS -
TEMPERATURES menu to determine if any sensors are currently displayed
as SHORT or OPEN. Compare this to the boiler temperatures recorded in the
DIAGNOSTICS - ERRORS - LOCKOUT HISTORY # - TEMPERATURES during
the last several lockout conditions.
Determine which sensors are suspect and measure their resistance value and
compare it to the values shown in Figure 86, page 92. 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.
Part number 550-100-561/0224