50A52 Flow Chart 4 - American Standard *UD Series Operation Manual

50A52 Flow Chart 4

Radiant
Sensor
Check
4A
YES
Does Main
Burner Remain Lit?
NO
Does Burner
Flame Pattern
Appear Normal?
YES
Is Radiant
Sensor Window Dirty?
NO
Is Radiant
Sensor and Ignitor
Positioned Correctly?
YES
Check Sensor
Contact Resistance.
Should be < 25 OHMS
Does Ignitor Remain
Energized with Flame
Present for More Than
1 second?
YES
NO Check Gas Pressure
or Clean Orifices.
Check Burner
Alignment.
YES
Clean
Window
NO
Repair and
Check Operation
4B
NO
Blower at
Heat Speed
within 45 sec of
Gas Valve On?
NO
Is 120 VAC Present at
Control Terminals Heat Circ.
and Heat Circ. Neu.?
NO
Replace
Control
Module
64
YES
System
Operation
Proper
YES
Repair Wiring
and/or Replace
Indoor Blower.
Check Operation.