lp-666 Rev. 003 Rel. 001 Date 2.25.20
67
Code
Message
Description
Possible Remedy
F01
Flue Temp
ECO
The dual flue sensor contains two sensing
elements within a single body. F01 indicates
that one or both halves of the supply
temperature sensor has failed OR the
difference between the dual sensor readings is
greater than 18
o
F. This is a serious safety issue
and the boiler will not restart until a qualified
service technician replaces the sensor and
pushes the
RESET
button on the display.
This situation is indicated by the red center
pane of the Home screen. The word LOCKOUT
will also be displayed. During this lockout
fault, the pump will be on.
1. Check the electrical connections to each half of the thermistor
on the outlet manifold. Verify 3.3 VDC by checking in Molex
connector. If there is not 3.3 VDC, check the harness. If harness and
sensors are OK, replace the control.
NOTE:
The boiler will reset automatically. Verify thermistor
resistance values of each half of the dual sensor by referencing the
chart in this manual.
2. Replace the thermistor if necessary.
F02
Lockout: F02
Supply
Sensor
The dual supply sensor contains two
sensing elements within a single body. F02
indicates that one or both halves of the
supply temperature sensor has failed OR the
difference between the dual sensor readings is
greater than 18
o
F. This is a serious safety issue
and the boiler will not restart until the sensor
is replaced by a technician and he pushes the
RESET
button on the display. This situation is
indicated by the red center pane of the Home
screen and the displayed phrase Lockout: F02
Supply Sensor. During this lockout fault, the
pump will be on.
1. Check the electrical connections to each half of the thermistor
on the outlet manifold. Verify 3.3 VDC by checking in Molex
connector. If there is not 3.3 VDC, check the harness. If harness and
sensors are OK, replace control.
NOTE: The boiler will reset automatically. Verify thermistor
resistance values of each half of the dual sensor by referencing
chart in this manual.
2. Replace thermistor if necessary.
F03
Lockout:
Return
Sensor
F03 indicates the return temperature sensor of
the boiler has failed. The boiler will not restart
until a technician replaces the sensor and
pushes
RESET
on the display. This is a serious
safety issue as indicated by the red center
pane of the Home screen and the displayed
phrase Lockout: F03 Return Sensor. During
this lockout fault, the pump will be on.
1. Check circulator pump operation.
2. Ensure adequate flow through the boiler by accessing the status
menu and determining there is less than a 50
o
F rise from the
return thermistor to the supply thermistor.
3. Troubleshoot thermistor by following the steps in F02.
F04
Lockout: F04
Flue Sensor
Interrupted
F04 indicates that the flue temperature
sensor of the boiler has failed. The boiler will
not restart until a technician replaces the
sensor and pushes
RESET
on the display. This
is a serious safety issue as indicated by the
red center pane of the Home screen and the
displayed phrase Lockout: F04 Flue Sensor
Interrupted. During this lockout fault, the
pump will be on.
Inspect the flue sensor for physical damage or corrosion and
replace it if necessary. Check the electrical connection to the flue
sensor and repair as necessary. Measure the resistance of the
sensor and refer to the sensor resistance table in this manual. The
temperature on the chart should be close to the temperature in
the flue. If not, replace the flue sensor.
F05
Blocking:
Supply
Temperature
High
OR
Lockout:
F05 Supply
Maximum
F05 indicates the boiler supply temperature
is excessive. When accompanied by the
red center pane of the Home screen and
the displayed phrase Lockout: F05 Supply
Maximum, this code indicates the supply
sensor temperature has exceeded 210
o
F and
a serious safety issue exists. The boiler will
not restart until a technician determines and
repairs the cause of excessive temperature
and pushes
RESET
on the display.
If the center pane of the Home screen is orange,
and the displayed phrase Blocking: Supply
Temperature High, the supply temperature of
the boiler is at or above 199
o
F. The message
will clear automatically when the temperature
drops below 194
o
F.
During the time that this fault is displayed, the
pump will be on.
1. Check circulator pump operation.
2. Ensure adequate flow through the boiler by accessing the status
menu and determining there is less than a 50°F rise from the return
thermistor to the supply thermistor.
3. Check the direction of flow off the boiler circulator. (See Piping
Details in this manual.)
4. Troubleshoot the dual supply thermistor by following steps in
F02.