Troubleshooting Guide - L.B. White Oval 90 v.2 Owner's Manual And Instructions

Troubleshooting
Information
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 THESE HEATERS
UNLESS YOU HAVE BEEN PROPERLY
TRAINED.
TEST EQUIPMENT REQUIRED
The following pieces of test equipment will be
required to troubleshoot this system with minimal time
and effort.
• 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.
■ Visually inspect equipment for apparent damage.
■ Check all wiring for loose connections and worn
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 esential
as it will relate directly to problem solving provided by
the flow charts.
The ignition control module is self-diagnostic. The red
LED on the burner box will flash a specific light
pattern depending upon the problem which is
diagnosed. To effectively use the flow charts, you
must first identify what the problem is by the light
pattern of the red diagnostic light.
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A flashing light indicates a problem.
The flash pattern will be followed by a pause and then a
repeat of the flash pattern until the problem is corrected.
Refer to the tables below to identify what page to refer
to when troubleshooting any problems.
Problems
ON L.E.D. light is not ON, heater is not operating ... 26
L.E.D. diagnostic light is flashing:
A. Rapid Flash .................................................... 27
B. One Time ........................................................ 27
C. Two Times ...................................................... 27
D. Three Times ................................................... 28
E. Four Times ..................................................... 28
F. Five Times ...................................................... 28
Components should be replaced only after each step
has been completed and replacement is suggested
in the flow chart. Refer to the Servicing sections as
necessary to obtain information on disassembly and
replacement procedures of the component once the
problem is identified by the flow chart.
DIRECT IGNITION OPERATION SEQUENCE:
-- Line voltage is sent to ignition control and to
transformer.
-- Transformer reduces line voltage to 24 volts which is
sent to ignition control.
-- Ignition control module performs self safety check.
-- Internal components are tested.
-- Air pressure switch circuit is checked.
-- Ignition control module begins ignition trial sequence.
-- Ignition control module sends 24 volts to air pressure
switch.
-- Ignition control sends line voltage to motor.
-- Fan motor starts.
-- Green LED is illuminated.
-- Air pressure switch contacts close and 24 volts are
returned to the ignition control module.
-- Ignition control module sends high voltage to the
igniter electrode.
-- Igniter sparks.
-- Ignition control module sends 24 volts to the gas
control valve.
-- Gas control valve opens.
-- Ignition occurs.
-- Igniter continues to spark for 4 seconds
-- Ignition spark is cut off.
-- Gas valve stays open.
-- Building controller shuts heater down.
-- Process starts again on a call for heat.
25
Page