Ultra Boiler Manual

Part number 550-100-440/0122
120
  
 (continued)
Display
Condition Diagnostics Corrective Action(s)
RETURN >
SUPPLY
Occurs when a return water
temperature is greater than
the corresponding supply
temperature by 10ºF or more.
Applies to system sensors or
boiler sensors.
Condition must occur for 10
minutes for system sensors.
Automatically resets when
condition no longer exists.
Verify proper ow direction of the boiler circulator. This circulator should
be installed to push water through the boiler's return pipe as shown in
Figure4,page11.
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 located further away from boiler loop
connection to the system if proximity to the boiler loop is causing
sensors to be heated inaccurately.
TEMPERATURE
SENSOR
Occurs when a temperature
sensor has electrically shorted
(SHORT) or has become
disconnected (OPEN).
Automatically resets when
condition no longer exists.
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123,page116. If the
resistance values are incorrect replace the temperature sensor. Refer to
repair parts section for proper part number.
OUTDOOR TEMP, SYSTEM SUPPLY, and SYSTEM RETURN 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
U-Control module. Unplug connection at sensor and at U-Control and
check continuity between ends.
If problem persists after checking items above replace U-Control. Refer
to repair parts section for kit number.
FLUE TEMP
TOO HIGH
Occurs when ue
temperature sensor exceeds
216ºF.
Automatic reset occurs if
temperature drops below 216ºF
for 2.5 min.
Manual reset is required if the
temperature rises above 225°F.
Reset using manual reset screen
on display.
Follow procedure for above for SHORT and OPEN sensor conditions
to properly diagnose sensor. In addition inspect heat exchanger
combustion chamber and ueways for abnormal wear or buildup.
Inspect vent system for abnormal wear or damage.
Contact WM Technologies Technical Support.
TEMPERATURE
SENSOR
Occurs when dual
temperature sensors values
have spread by more that
10ºF.
Automatically resets when
sensors are within 10ºF.
Follow procedure for above for SHORT and OPEN sensor conditions
to properly diagnose sensor. If measured resistance values of sensors
convert to temperatures separated by more than 10ºF replace the sensor.
LOW WTR
CUTOFF OPEN
Occurs when Low Water
Cuto Device contacts open
for more than 1 second.
Requires manual reset of
U-Control and may require
manual reset of LWCO device
depending on model.
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 Cuto. If shown as OPEN check wiring between
LWCO and U-Control.
 (continued)
Figure 125 Troubleshooting suggestions for Ultra boilers (continued)