L.B. White I-40 Infraconic Spark Ignition - Manual (Page 19)

18
READ THIS ENTIRE SECTION BEFORE
BEGINNING TO TROUBLESHOOT PROBLEMS.
The following troubleshooting flow charts provide systematic
procedures for isolating heater problems. The charts are
intended for use by a QUALIFIED GAS HEATER SERVICE
PERSON. DO NOT SERVICE THE HEATER 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 voltage.
• Pressure Gauge - (Part No. 20736) For checking inlet
pressures to the heaters.
INITIAL PREPARATION
-- Inspect the heater for damage.
-- Clean the heater as necessary.
Heater Problems Page
1. Heater does not light . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
2. Heater lights, but will not stay lit . . . . . . . . . . . . . . . . . . .20
3. Heater backflashes gas through air inlet . . . . . . . . . . . .20
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.
OPERATION SEQUENCE:
-- A call for heat occurs from building thermostat.
-- Line voltage is sent from building’s temperature control
to heater’s ON/OFF switch.
-- Switch sends power to ignition control.
-- Ignition control module begins ignition trial sequence
-- Ignition control sends high voltage to igniter
electrode
-- Igniter sparks
-- Gas control solenoid opens
-- Ignition occurs
-- Igniter continues to spark for 10 seconds until
flame proving occurs
-- Ignition spark is shut off
-- Gas control solenoid stays open
-- Ground warms to desired temperature
-- Building thermostat is satisfied
-- Heater shuts down
-- Process is repeated on a call for heat
IGNITION FAILURE SEQUENCE:
-- Ignition control will make three ignition trials
-- Each trial lasts 10 seconds
-- 15 seconds time span between each trial
-- If ignition control does not establish flame sense within
ignition trial:
-- Ignition spark shuts off
-- Gas valve closes
-- After three ignition trials, ignition control will wait for 15
minutes before retrying for ignition.
-- This process will be repeated continually until the
ignition problem is solved.
-- To manually reset the ignition control:
-- Unplug the heater and plug it back in
OR
-- Turn the building temperature control to off and
then back on.
OR
-- Turn ON/OFF switch on heater off and then on.
Troubleshooting Guide
WARNING
Electrical Shock and Burn Hazard
■
Troubleshooting this system may require operating the
heater with the burner on. Use extreme caution when
working on the heater.
■
Failure to follow this warning may result in electrical
shock or burns causing severe injury.