Service Manual
SERVICING
32
GAS HEATING ANALYSIS CHART
Com p laint No He at Uns atis factor y He at
POSSIBLE CAUSE
DOTS IN ANALYSIS
GUIDE INDICATE
"POSSIBLE CAUSE"
SYMPTOM
System Will Not Start
Burner Won't Ignite
Burner Ignites-Locks Out
Burner Shuts Off prior to T'Stat being Satasfi
e
Short Cycles
Long Cycles
Soot and /or Fumes
To Much Heat
Not Enough Heat
Test Method
Remedy
See Service Procedure Reference
Pow er Failure
•
Tes t V oltage S-1
Blow n Fuse
•
Tes t V oltage S-4
Loos e Connection
•
Chec k Wiring S-2
Shorted or Broken Wires
•
Chec k Wiring S-3
No Low Voltage
•
Check Transformer S-4
Faulty Thermostat
••••
Check Thermostat S-3
Faulty Transformer
•
Check Transformer S-4
Poor or High Resistance Ground
•
Measure Ground Resistance S-313
Improper Heat Anticipator Setting
•• ••
Adjust Heat Anticipator Setting S-3
Improper Thermostat Location
•• ••
Relocate Thermostat
Faulty Limit or Roll Out Sw itch
•• •
Test Control S-300,S-301,S-302
Faulty Flame Sensor
•
Test Flame Sensor S-314
Faulty Ignition Control
•••
Test Control S-313
Gas Valve or Gas Supply Shut Off
•
Turn Valves to On Position S-304
Faulty Induced Draft Blow er
•• •
Test Blow er S-303
Dirty Flame Sensor, Low uA
•
Clean Flame Sensor S-314
Flame Sensor not in Flame, Low uA
•
Test/Adjust Position of Flame Sensor S-314
Faulty Gas Valve
•••
Replace Gas Valve S-304
No High Stage Heat (2 Stage Only)
••
Check Thermostat, Control, Gas Valve S-3,S-313,S-304
Open A ux illary Limit
••
Reset Control S-301
Improper Air Flow or Distribution
••
Check Duct Static
Locking out on Main Limit
•• •
Check Controls, Gas Press., & Temp. Rise S-300
Delayed Ignition
•
Test for Delayed Ignition S-308
Flashback
•
Test for Flashback S-309
Orifice Size
•••
Check Orifices S-306
Gas Pressure
••••
Check Gas Pressure S-307
Cracked Heat Exchanger
•
Check Burner Flames S-302
Stuck Gas Valve
•••
Replace Gas Valve S-304
Furnace Undersized
•
Replace w ith Proper Size Furnace
Faulty Pressure Sw itc h
•••
Test Pressure Sw itch S-310
Blocked or Restricted Flue
•
Check Flue/Draw dow n Pressure S-310
Open Roll Out Sw itch
••
Test Control S-302
Bouncing On Pressure Sw itch
••
Test Negative Pressure S-310