L.B. White Journeyman Owner's Manual page 25

Troubleshooting Guide
READ THIS ENTIRE SECTION
BEFORE BEGINNING TO
TROUBLESHOOT PROBLEMS.
WARNING
■ This heater can start at any time.
■ Troubleshooting this system may require
operating the unit with line voltage present
and gas on.
■ Use extreme caution when working on the
heater.
■ Failure to follow this warning may result in
property damage, personal injury or death.
The following troubleshooting guide provides procedures
for isolating equipment problems. This guide is intended
for use by a QUALIFIED GAS HEATER SERVICE
PERSON. DO NOT ATTEMPT TO SERVICE THIS
HEATERS UNLESS YOU HAVE BEEN PROPERLY
TRAINED.
TEST EQUIPMENT REQUIRED:
• Digital Multimeter - for measuring AC voltage and
resistance
• Low Pressure Gauge - for checking inlet and outlet
pressures at the gas control valve against dataplate
rating
Before Starting:
• Visually inspect equipment for apparent damage.
• Check all wiring for loose connections and worn
insulation.
Components should be replaced only after each step has
been completed and replacement is suggested. Refer to
the Servicing sections as necessary to obtain
information on disassembly and replacement procedures
of the component once the problem is identified. Refer to
the system operation sequence in this section to gain an
understanding as to how the equipment operates during a
call for heat. Understanding the sequence of operation of
the ignition module and related components is essential
as it will relate directly to problem solving provided by the
charts.
Journeyman Ductable Dual Fuel Indirect-Fired Heater
Owner's Manual • Journeyman
OPERATION SEQUENCE:
• Line voltage is connected to the heater power
receptacle.
• Line voltage is sent to:
- POWER green light
- Fan switch
- Main motor relay
- Selector switch
• Set the selector switch to either MANUAL or
THERMOSTAT position.
- Thermostat selector switch sends voltage through both
auto high limit switches to the burner controller.
• Burner control performs an internal components test.
• Burner motor will starts and perform a 30 seconds
pre-purge.
• After the 30 seconds pre-purge, the ignition electrode and
solenoid will be energized.
• Ignition occurs.
• The burner will heat up the heat exchanger.
- The main motor will not start right away.
• Once the heat exchanger has reach a certain
temperature, the fan switch will energized the main
motor relay.
• The main motor will start.
• If the selector switch is set to OFF position or thermostat
opens due to heat demand is satisfied.
- The burner control shuts off the burner.
- Main motor will not stop right away.
- The main motor will continue to operate to cool down the
heat exchanger (post purge).
• After the post purge, the fan switch will de-energize the
main motor relay.
- The main motor stops.
• Process will start again on a call for heat by the
thermostat or the thermostat selector switch is set to
MANUAL position.
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