L.B. White Pilot - Manual (Page 35)

Troubleshooting Guide
Troubleshooting
Instructions
READ THIS ENTIRE SECTION BEFORE
BEGINNING TO TROUBLESHOOT PROBLEMS.
The troubleshooting flow charts in this section provide
systematic procedures for isolating heater problems. Refer
to the Component Testing section of this Service Guide for
general instructions on performing voltage and continuity
checks as well as evaluation of specific components as
indicated by these charts. Refer to the appropriate wiring
diagram for assistance in performing voltage and continuity
checks. Refer to the Service section for gas pressure checks
and adjustments as indicated by the flow charts.
TEST EQUIPMENT REQUIRED
The following pieces of test equipment will be required to
troubleshoot this system with minimal time and effort.
• Digital M Multimeter - for measuring voltage and resistance.
• Thermocouple TTest K Kit - (L. B. White Part No. 500-08506)
When used with a standard digital multimeter, this kit
allows testing of the power unit of the pilot safety control
and thermocouple on pilot ignition systems.
• Low PPressure G Gauge - (L.B. White Part No. 550-00764) for
checking inlet and manifold pressures of the gas control
valve against dataplate rating.
INITIAL PREPARATION
■ Visually inspect heater for apparent damage.
■ Check all hoses for abrasion and wear. Replace any
that are suspect.
■ Make sure heater is properly installed and meets
minimum clearances to nearest combustible materials.
(Refer to dataplate on heater.)
■ Check all wiring for loose connections and worn
insulation.
To effectively use these flow charts, you must first identify
the problem. The problems are numbered sequentially,
along with a brief explanation of each problem. Start at the
“diamond” closest to the identified problem and proceed
with each step, performing the suggested tests. After each
step or test, the guide will direct the service person to the
next logical step based on the outcome of the previous
check.
The problems are listed below along with the page number
on which you may find the flow chart for the specific
problem.
Problem Description Page
1 Pilot will not light 5.1-3
2 Pilot will not stay lit when pilot control
button is released 5.1-4
3 Motor runs. Burner does not light with
pilot light lit. 5.1-5
4 Motor does not run, heater does not light
with pilot light lit. 5.1-6
5 Main burner cycles on and off repetitively.
Pilot stays lit. 5.1-7
6 Pilot will not stay lit when main burner
and blower are operating. 5.1-7
7 High limit switch is open. 5.1-8
8 Burner does not shut off. 5.1-9
9 Flame “lifting” off of burner. 5.1-9
10 Burner flame drops out after 10 - 15
minutes of operation. 5.1-9
11 Gas control valve “chatters”. 5.1-10
12 Motor “hums”. 5.1-10
13 Heater is not delivering proper air flow 5.1-11
14 Heater is not delivering proper heat output 5.1-11
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.
Additionally, a series of illustrations has been provided on
the following page to identify typical problems based upon
pilot flame appearances.
August 1999
5.1-1 1
WARNING
Electrical S Shock aand B Burn H Hazard
■ Do not attempt to service or repair this heater unless
you are a properly trained and qualified gas heater
service person.
■ 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.