Pioneer PHR100-55, Instruction Manual

Page: 57 / 65

57
926 CONTROL BOARD ERROR CODES
CODE DESCRIPTION CORRECTIVE ACTION
Fou
Outdoor sensor shorted
or temperature less than -
40
o
F
Inspect wiring from outdoor sensor for damage or shorted connections and repair as
necessary. Measure resistance of outdoor sensor and compare to resistance chart. If not
within range on chart, shorted or open, replace sensor.
E19
Line voltage frequency
out of range.
Inspect power wiring to appliance and repair as necessary. If connected to line voltage,
notify power company. If connected to an alternate power source, such as a generator or
inverter, make sure line voltage frequency supplied by the device is 60 Hz.
FLU
Blocked Vent Pressure
Switch open, Condensate
cup Full, Condensate Cup
not present
1. Check the flue vent to be sure it is not blocked or damaged.
2. Check the blocked vent pressure switch operation by applying a jumper.
(If the switch is not functioning properly, replace it.
LEO Water Level in Tank is
Low 1. Be sure all air is bled from system.
2. Inspect low level switch and wiring for damage and repair if necessary.
LOU 24 Volt Low
1. Check line voltage. Must be between 100 – 128 volts.
2. If available, connect a 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 greater than 250. Use this as a troubleshooting guide as you follow the steps
below.
3. Remove 10 pin Molex connector from customer connection board. If LOU clears, then the
problem is with external sensor wiring. Examine external sensor wiring for shorts to ground,
repairing as necessary. If LOU code is still present and the heater is so equipped,
disconnect high gas pressure switch, then low gas pressure switch, then UL 353 low water
cutoff in this order, one at a time, to see if LOU code clears. Replace faulty part. Check low
voltage wire harness in heater for shorts to ground.
4. If LOU only occurs when burner tries to light, check gas valve for excessive current draw.
5. If LOU is present with the low voltage harness disconnected from the 926 control board,
replace the 926 control board.
E03
System sensor failure
(Cascade Master only)
1. Check wiring to system sensor. Repair as necessary.
2. Check sensor resistance. Compare to the resistance table in this manual. Replace if not
correct.
FL
Low water flow (Users
with optional flow switch
only).
1. Check to see if appliance circulator is functioning. Repair as necessary.
2. Be sure water is flowing in the system. Check for valves that should be open, plugged
filter screens, etc.
3. Check flow switch and wiring. Repair as necessary.
Table 15
926 Control Board FAULT
Codes Description Remedy
F00
High temperature switch limit
exceeded 194
o
F.
1. Try reset. If F00 repeats, create a demand for hot water. (DANGER: Use caution to
prevent burn injury.) If water is above 194
o
F, test upper and lower temperature sensor
with an ohmmeter. (Refer to resistance chart, this section.) Replace bad sensor. If water
is below 194
o
F, test high temperature switch and wiring with ohmmeter. Switch should
be closed at this point. If not, replace switch.
2. If unit did reset successfully, let the heater run and go into the status menu to check
the upper and lower temperature sensor. If either reading displayed does not make
sense, check appropriate sensor with ohmmeter. (Refer to resistance chart, this section.)
Replace bad sensor. Do an OHMs reading on both sensors to check continuity.
F01
Vent temperature limit
exceeded.
1. Inspect all flue piping. If the flue is damaged or shows signs of overheating, repair or
replace the flue parts as necessary before proceeding.
2. If the flue piping system is intact and there is no sign of the flue overheating (such as
discoloration or melting), push the red reset button on the flue switch.
3. Be sure the heater is connected to a water supply and full of water.
4. Push the RESET button on the heater control panel. The appliance should light. If the
appliance lights, proceed to step 5. If the appliance does not light and the display again
begins to flash F01, inspect the wiring to the flue switch, repairing or replacing as
necessary. If the wiring is intact, replace the flue switch, using care to mount the new
flue switch in the same position and mounting holes as the old one. If the display flashes
a code other than F01, follow the troubleshooting guide for that code.
5. Observe operation for 5 minutes. Place the probe of an exhaust analyzer into the flue
system within 6 feet of the heater. The exhaust temperature should not rise above 190
o
F
after several minutes of operation.
6. If the flue temperature is below 190
o
F and the heater again goes into lockout
displaying F01, replace the flue switch, using care to mount the new flue switch in the
same position and mounting holes as the old one. If the display flashes a code other
than F01, follow the troubleshooting guide for that code.
7. If the flue temperature increases to over 190
o
F, consult HTP for further assistance.