CONQUEST 80 - IFC Troubleshooting Guide

82
FIGURE 89
INTEGRATED FURNACE CONTROL (IFC) UTEC 1012-920, UTEC 1012-920A, AND HONEYWELL S9201E2001
TROUBLESHOOTING GUIDE (115 VAC HOT SURFACE IGNITER)
START
NO
• REMOVE (IFC) COVER, CHECK LIGHTS
POWER LED ON
~
• CHECK LINE VOLTAGE POWER
NO
• CHECK LOW VOLTAGE TRANSFORMER
• CHECK LOW VOLTAGE TRANSFORMER FUSE
, YES
NO
REPLACE (IFC)
CHECK THERMOSTAT
WIRING
REPLACE SWITCH
I
~
REPLACE (IFC)
IF WIRING TO
IDM MOTOR IS OK
,,
NO
NO
REPLACE SWITCH
I
IGNITER WARMS UP
AND GLOWS RED
30 SECONDS WARMUP
REPLACE (IFC)
YES IF WIRING TO
IGNITER IS OK
,.
MAIN BURNER
~
LIGHTS
YES
t
FLOW CHART CONTINUED ON NEXT PAGE
WARNING
ll
DISCONNECT POWER BEFORE
HAZARDOUS VOLTAGE
SERVICING.
LINE VOLTAGE
SERVICE MUST BE BY A TRAINED,
CONNECTIONS
QUALIFIED SERVICE TECHNICIAN.
1. SET FAN SWITCH TO AUTO
2. SET THERMOSTAT TO
CALL FOR HEAT
INDUCED DRAFT MOTOR
I
(IDM) STARTS
YES
-
MICROPROCESSOR STATUS LED ON
YES
CHECK FOR 24 VAC FROM
~
TERMINAL "W" TO "C" ON IFC
• CHECK LIMITS, (CLOSED)
• CHECK WIRING
• CHECK PRESSURE SWITCH, (OPEN)
NO
IF THE PRESSURE SWITCH DOESN'T
CLOSE WITHIN 60 SEC. THE IDM WILL
STOP FOR 5
MIN. AND RETRY
~
• CHECK FOR 115VAC TO IDM MOTOR
-
If
30 SEC. PREPURGE
YES
-
YES
REPLACE IDM MOTOR
• CHECK FOR BLOCKED VENT
• CHECK AIR PROVING SWITCH (CLOSED)
• CHECK WIRING TO IGNITER
~
• CHECK FOR 115 VAC AT IGNITER,
TERMINALS AND AT (IFC) TERMINALS
YES
REPLACE IGNITER
I
SYSTEM WILL ATTEMPT TO LIGHT 4 TIMES. VOLTAGE IS PRESENT
AT THE VALVE FOR ONLY 7 SECONDS DURING EACH TRIAL FOR
IGNITION (SYSTEM WILL GO INTO A 1-HOUR LOCKOUT AFTER
4 TRIES). THE BLOWER AND INDUCED DRAFT BLOWER WILL RUN
180 SEC. IF THE FIRST IGNITION TRIAL FAILS TO SENSE FLAME
• CHECK FOR 24 VAC ACROSS THE VALVE AND
VALVE TERMINALS ON THE (IFC)
• CHECK IGNITER POSITION
I
• CHECK FOR GAS FLOW TO AND FROM VALVE
NO
NO
,
REPLACE VALVE REPLACE (IFC)
IF WIRING TO
VALVE IS OK