lp-445-r4 Rev. 006 Rel. 027 Date 7.21.20
52
SUPPLY SENSOR F02
PUMP ON
F02 indicates the supply 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
illuminated red light and the word LOCKOUT
flashing on the display. During this lockout
fault, the pump will be on.
1. Check the electrical connection to the thermistor on
the outlet manifold. Verify 5 VDC by checking the Molex
connector. If there is no 5 VDC, check the harness. If
harness is OK, replace the control. Verify thermistor
values by referencing chart in this manual.
2. Replace thermistor if necessary.
NOTE:
The boiler will reset automatically once the fault
is corrected.
RETURN SENSOR F03
PUMP ON
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
illuminated red light and the word LOCKOUT
flashing on the display. 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.
FLUE SENSOR F04
PUMP ON
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 illuminated red light and the word
LOCKOUT flashing on the display. 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.
Screen
Description
Possible Remedy
SUPPLY TEMP HIGH F05
PUMP ON
F05 indicates the boiler supply temperature
is excessive. When accompanied by the
red FAULT light and LOCKOUT flashing on
the display, this code indicates the supply
sensor temperature has exceeded 230
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 FAULT light is not illuminated and
this message is displayed, the supply tem-
perature of the boiler is at or above 210
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 thermistor by following steps in F02.
RETURN TEMP HIGH F06
PUMP ON
This display indicates that the boiler
return temperature is excessive. When
accompanied by the red FAULT light and
LOCKOUT flashing on the display, this code
indicates that the return sensor temperature
has exceeded 230
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 red FAULT light is not illuminated and
this message is displayed, then the return
temperature of the boiler is at or above
210
o
F. The message will clear automatically
when the temperature drops below 194
o
F.
During the time that this message or lockout
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 on boiler circulator. (See
Piping Details in this manual.)
4. Troubleshoot thermistor by following steps in F02.
