Troubleshooting Guide - L.B. White I17 Owner's Manual And Installation Instructions

Troubleshooting Guide

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 N N OT S S ERVICE T T HE H H EATER U U NLESS Y Y OU H H AVE
BEEN P P ROPERLY T T RAINED.
TEST EQUIPMENT REQUIRED
The following pieces of test equipment will be required to
troubleshoot this system with minimal time and effort.
• Digital M M ultimeter - For measuring AC voltage.
• High P P ressure G G auge - (L. B. White Part No. 500-20736)
For checking inlet pressures to the heaters.
Electrical S S hock a a nd B B urn H H azard
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 property
damage, personal injury or death.
INITIAL PREPARATION
1. Visually inspect equipment for apparent damage.
2. Check all wires and gas hoses for abrasion and wear.
Replace any that are suspect.
3. Make sure the heater is properly installed and meets
minimum clearances to nearest combustible
materials. (Refer to dataplate on the heater, also on
page 4 of this manual.)
Heater P P roblems
1. Heater does not light . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
2. Heater lights, but will not stay lit . . . . . . . . . . . . . . . . . . .21
3. Burner flame extending beyond outer cone
or black soot on inside of canopy . . . . . . . . . . . . . . . . . .22
19
WARNING
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 through high
limit switch when positioned to ON.
-- 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.
Page
-- To manually reset the ignition control:
-- Unplug the heater and plug it back in
-- Turn the building temperature to off and then
back on.
OR