LP-314 Rev. 012 Rel. 003 Date 9.27.19
44
LINE VOLTAGE
PUMP OFF E19
The line voltage frequency is out of range. This
could happen if the unit is being powered from
a small gasoline powered generator that is not
functioning correctly or overloaded.
Inspect power wiring to unit and repair as necessary. If
connected to line voltage, notify electric utility company. If
connected to an alternate power source such as generator
or inverter, make sure the line voltage frequency supplied by
the device is 60 Hz.
HIGH FLUE PRESS FLU
PUMP ON
FLU indicates excessive flue pressure. This code
resets automatically after the high pressure
condition is resolved. The second line indicates
pump status.
1. Ensure the flue is not blocked.
2. Check the switch wiring by applying a jumper in place
of the switch. If the code clears with the jumper in place,
REPLACE the flue switch and connect the wires to the new
switch BEFORE running appliance.
WARNING:
Do not use jumper to remedy an FLU error. Faulty switch MUST be replaced. Failure to follow this instruction could result in
serious personal injury or death.
LOW WATER LEVEL
PUMP OFF LEO
LEO indicates low water level in the main tank.
This code will not allow the unit to run until
correct water level is restored. The second line
indicates the status of the pump. NOTE: While the
water level is low, the pump will be off.
1. Ensure there is adequate pressure and flow through the
cold water inlet by slightly opening the drain valve near the
tank.
2. Ensure the DHW system has all air removed through a high
point hot water source, i.e. sink faucet.
3. Check wiring and probes. Replace if necessary.
24 VOLT LOW
PUMP ON LOU
LOU indicates the 24 volt power supply on the
control is damaged or overloaded. This code will
reset 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: While 24 volt power is low, the pump
output will be on.
1. Ensure line voltage is between 100-128 volts.
2. Disconnect TT wiring. If error clears, there is an issue in the
thermostat wiring. Review external wiring.
3. If available, connect a PC and use HTP service software to
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 at least 250. Use this as a troubleshooting
guide as you follow the steps below.
4. Remove the 12 pin Molex connector from the field wiring
board. If the message clears, then the problem is with external
low voltage wiring. Examine the external low voltage sensor
wiring for shorts to ground and repair as necessary. If message
is still present, disconnect the UL 353 low water cutoff to see
if message clears. Replace faulty part. Check low voltage wire
harness in appliance for shorts to ground.
5. Remove the 20 pin Molex from the ECS board. If the
message clears, examine the wiring to the heating module
and fan for shorts or grounds and repair as necessary.
6. If message only occurs when the burner tries to light, check
gas valve for excessive current draw.
7. If message is present with the low voltage harness
disconnected from the 926 control board, replace the 926
control board.
The following blocking codes will block operation until the control determines the situation safe for appliance operation.
WATER HIGH TEMP
PUMP ON F00
F00 indicates the water in the tank has overheated.
This is a serious safety issue, as indicated by the
red fault light and the flashing word LOCKOUT on
the display. The unit will not restart until it cools
sufficiently and a technician repairs the cause
of overheating and resets the unit. During this
lockout fault, the pump will be on as indicated on
the second line of the display in an effort to cool
down the appliance.
1. Check central heating pump operation.
2. If the circulator pump is running, ensure there is water in
the system and that water is moving through the system as
intended. Ensure that all ball valves and or zone valves are
open or closed as intended.
3. Observe the temperature/pressure gauge. If the water is
not hot and this message is displayed, check the wiring to the
water eco sensor and repair if necessary.
4. If the wiring is intact, water is not excessively hot and this
code is still present, replace the eco sensor.
FLUE TEMP
PUMP ON F01
This display indicates that the flue temperature
limit switch of the unit has tripped. This is a serious
safety issue, as indicated by the red fault light and
LOCKOUT flashing on the display. The unit will
not restart until the flue cools sufficiently and a
technician repairs the cause of the problem and
pushes the
RESET
button on both the device and
the display. During this lockout fault, the pump
will be on as indicated on the second line of the
display.
1. Check the flue for obstructions or any sign of damage
(especially signs of excessive heat). Repair as necessary.
2. Push the red reset button on the flue temperature switch
located on CPVC vent elbow. NOTE: Switch temperature must
be less than 90°F to reset.
3. Press
RESET
on the display. Run the unit and check the flue
temperature by using an external thermometer in the flue
pipe. If the flue temperature is below 190°F and the switch
trips, replace the switch. If the flue temperature is excessive,
check and adjust the combustion controls on the unit.