Troubleshooting Information - L.B.White Sentry ST60 Manual Del Propietário

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 proce-
dures 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.
■ Checki all wiring for loose connections and worn
Refer to the system operation sequence in this
section to gain an understanding as to how the equip-
ment 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 fl ow charts.
The ignition control module is self-diagnostic. The red
LED on the burner box will fl ash a specifi c light pat-
tern depending upon the problem which is diagnosed.
To effectively use the fl ow charts, you must fi rst
identify what the problem is by the light pattern of the
red diagnostic light.
Sentry Tube Heaters
A fl ashing light indicates a problem.
The fl ash pattern will be followed by a pause and then a
repeat of the fl ash 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 27
L.E.D. diagnostic light is fl ashing:
A. Rapid Flash ................................................... 28
B. One Time ....................................................... 28
C. Two Time ....................................................... 28
D. Three Time .................................................... 29
E. Four Time ...................................................... 29
F. Five Time ....................................................... 29
Components should be replaced only after each step
has been completed and replacement is suggested
in the fl ow chart. Refer to the Servicing sections as
necessary to obtain information on disassembly and
replacement procedures of the component once the
problem is identifi ed by the fl ow 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 the 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.
-- Green light is illuminated
-- Fan motor starts.
-- 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.
-- Room warms to desired temperature.
-- Thermostat is satisfi ed.
-- Heater shuts down.
-- Process starts again on a call for heat.
Owner's Manual • Sentry
25
Page