Hurricane SCH25, Service And Troubleshooting Manual

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Page 21
Test Point Component Results / Optimal Condition
TP9 Overheat
Aquastat
The voltage will be 0 volts if an overheat
condition is occurring or has occurred in the past
two minutes (overheat aquastat is open). The
voltage will be between 4.8 and 5 volts if the
overheat aquastat is closed.
TP10 Voltage
Fault
The voltage will be 0 volts if there is no voltage
fault, and between 4.8 and 5 volts when there is
a voltage fault.
TP11 Remote
Switch
The voltage will be 0 volts when the remote
switch is off, and between 4.8 and 5 volts when
the switch is on.
TP12 Reset The voltage will be 0 volts when the reset button
is pressed, and between 4.8 and 5 volts when
the reset button is not engaged.
TP13 Thermostats
Or Domestic
Water
The voltage will be 0 volts when the thermostat
or domestic water system calls for heat and
between 4.8 and 5 volts when heat is not called
for.
TP14 Blown Fuse Blown fuses for the burner, pump, or cabin fans
will show a voltage of between 4.8 and 5 volts.
Good fuses will show 0 volts.
3.20. LCD Readout Remote Panel
This panel will display the diagnostic explanation, which will match up to
the diagnostic code on the main board. A small buzzer will sound for 10
seconds to alert you of a fault.
If the LCD panel does not display anything when the heater is switched
on, insert a paper clip in the right hand hole to press the reset button.
3.21. Flame Sensor Module
The Flame Sensor consists of a sealed module with a photodiode aimed
at the flame, a red LED indicator light and 3 wires, red (+), black (-),
and yellow (signal) connected to the main board. Under normal
operating conditions whenever the burner ignition begins, the red LED
will flash once indicating the red and black wires are connected and the
module is receiving power and working properly. Once the burner is
ignited, the LED will begin to flicker like the flame. If for any reason the
flame is extinguished, the flickering will stop and the board will shut
down the heater. If the yellow (signal) wire is disconnected, the board
will shut down. If all the wires are properly connected with module