Manual

68
LP- 293 REV. 5.20.14
Fault Code LOU
24 VOLT LOW LOU
PUMP ON
This display indicates that the 24 volt power
supply on the control is damaged or overloaded.
This code resets automatically if it is the result of
an overload and that overload condition is
removed. The second line indicates the status of
the pump. Note that while 24 volt power is low,
the pump output will be on.
1. Check line voltage. It must be between 100 and
128 volts.
2. If available, connect PC, and using HTP service
software check the 24v supply display in the lower
left corner of the screen. The number displayed
here must be greater than 128 and should be no
greater than 250. Use this as a troubleshooting
guide as you follow the steps below.
3. Remove the 10 pin Molex connector from
customer connection board. If the message clears,
then the problem is with the external sensor wiring.
Examine the external sensor wiring for shorts to the
ground, repairing as necessary. If the message is
still present and the boiler is so equipped,
disconnect the UL 353 low water cut-off to see if
the message clears. Replace the faulty part. Check
the low voltage wire harness in boiler for shorts to
ground.
4. If a message only occurs when the burner tries
to light, check the gas valve for excessive current
draw.
5. If a message is present with the low voltage
harness disconnected from the 926 control board,
replace the 926 control board.
Fault Code F00
WATER HIGH TEMP F00
PUMP ON
This display indicates if the water in the boiler has
overheated. This code indicates a serious safety
issue and the boiler will not restart until it cools
sufficiently and a technician repairs the cause of
overheating and pushes the RESET button on the
display. This is a serious situation and is indicated
by the red light on the display illuminating and the
word LOCKOUT flashing on the display. During
this lockout fault, the pump will be on as indicated
on the second line in an effort to cool the boiler
down.
1. Check circulator pump operation
2. If the circulator pump is running, be sure that
there is water in the system and that the water is
moving through the system as intended. Be sure
that all correct ball valves and or zone valves are
open or closed as intended.
3. Observe the temperature/pressure gauge. If the
water is not too hot and this message is displayed,
check the wiring to the water ECO sensor and
repair if necessary. If the wiring is ok and this code
is still present and the water is not excessively hot,
replace the ECO sensor.
Fault Code F01
FLUE TEMP/WAT LV F01
PUMP ON
This code indicates that one of the safety
interlock switches present in the unit has
tripped. There are several interlock
switches that could possibly trip and cause
this error. The following switches are
installed standard equipment in all boilers.
1. Flue ECO – Trips if the flue
temperature is excessive. This switch
has to be manually reset.
2. Blocked vent pressure switch (BVPS)
– This switch trips if there is excessive
pressure in the flue and automatically
resets.
3. (EL-299 / 301 / 399 models ONLY)
Boiler module front temperature switch
- Trips if there is excessive heat on the
front of the heat exchanger.
The UL 353 Low Water Cutoff (LWCO) is
optional and may be installed on the boiler.
This device trips if the water level in the
boiler is low. This switch must be manually
reset.
1. Check to see if the boiler with the F01 code
displayed has an optional UL 353 LWCO installed.
2. If so, check to see if the indicator light on shows that
the LWCO has tripped.
3. If the LWCO has tripped, restore the proper water
level. Then manually reset the switch and boiler.
4. If there are no optional switches or none of the
indicator lights is illuminated on the optional switches
then use an ohmmeter to test each of the standard
switches one at a time. Turn the power off to the
boiler and disconnect the switch to be tested from the
boiler to determine which one has tripped.
When you find the tripped switch investigate the
cause of the fault based on the purpose of the
switch. NOTE: The common reasons for the
temperature switches to trip are a) low water flow
through the boiler, or b) poor heat transfer from the
water to the load.
5. If no switches are tripped, push RESET on the boiler.
If the boiler tries to ignite or ignites and only runs for
a short time and the F01 code returns, investigate
the flue for blockage.
Fault Code F02
SUPPLY SENSOR F02
PUMP ON
Indicates that the supply temperature sensor of
the boiler has failed. 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 light on the display and the
flashing word LOCKOUT. During this lockout fault,
the pump will be on as indicated on the second
line of the display.
1. Check the electrical connection to the thermistor
on the outlet manifold. Verify 5 VDC by checking in
Molex connector. If there is no 5 VDC, check the
harness. If harness is OK, replace control. NOTE:
The boiler will reset automatically. Verify thermistor
values by referencing chart in this manual.
2. Replace thermistor if necessary.