Rheem H2AC Installation Instructions Manual page 44

FIGURE 21
FURNACE TROUBLESHOOTING GUIDE
(COMBINATION HEATING AND COOLING UNITS WITH DIRECT SPARK IGNITION)
START
SET THERMOSTAT TO
CALL FOR HEAT
SET FAN SWITCH TO AUTO
YES
INDUCED DRAFT BLOWER
MOTOR STARTS
YES
30 SECOND PREPURGE
YES
IGNITOR SPARKS
YES
MAIN BURNER LIGHTS
YES
44
WARNING
HAZARDOUS VOLTAGE
DISCONNECT POWER BEFORE
LINE VOLTAGE CON-
SERVICING.
NECTIONS
SERVICE MUST BE BY A TRAINED,
QUALIFIED SERVICE TECHNICIAN.
• CHECK LINE VOLTAGE TO IFC
NO • CHECK LOW VOLTAGE TRANSFORMER
• CHECK WIRING
• CHECK FOR 208-230 VAC OR 460V TO IDM MOTOR
REPLACE INDUCED
DRAFT BLOWER(S)
NO • CHECK IGNITOR CABLE
• CHECK SPARK IGNITOR POSITION AND CONDITION
• IS EACH NEGATIVE PRESSURE SWITCH CLOSED?
• CHECK FOR OPEN ROLL-OUT CONTROLS
• CHECK FOR OPEN LIMIT
• CHECK IGNITION CONTROL CHASSIS GROUND WIRE
• CHECK WIRING
REPLACE IGNITION CON-
NOTE: THE SYSTEM WILL ATTEMPT TO LIGHT 3 TIMES WITH A 60 SECOND INTER-
PURGE BETWEEN TRIES. IF AFTER THE THIRD TIME THE BURNERS
DO NOT LIGHT, THE SYSTEM WILL LOCK OUT. IF THE UNIT IS EQUIPPED WITH
A UNITED TECH. THE SYSTEM WILL ATTEMPT TO LIGHT 3 TIMES EACH HOUR
UNTIL THE BURNERS LIGHT OR THE THERMOSTAT IS RESET OR POWER IS
REMOVED FOR 3 SECONDS OR GREATER.
NO
• CHECK INLET GAS PRESSURE
• CHECK 24 VOLTS TO GAS VALVE
• CHECK FOR GAS FLOW TO AND FROM VALVE
• CHECK BURNER CARRYOVER
REPLACE VALVE
FLOW CHART CONTINUED ON NEXT PAGE
YES
YES
YES
YES
NO
TROL
YES
REPLACE INTEGRATED
CONTROL BOARD (IFC)
NO
REPLACE IGNITOR/
CABLE ASSEMBLY
• CHECK NEGATIVE PRESSURE
SWITCH SENSING TUBE
• CHECK FOR EXHAUST
BLOCKAGE
NO
NO
REPLACE NEGATIVE
PRESSURE SWITCH
CHECK FOR EXHAUST,
INTAKE OR HEAT
EXCHANGER BLOCKAGE
AND RESET CONTROL
REPLACE LIMIT
IF UNIT IS COLD
REPLACE INTEGRATED
NO
CONTROL BOARD (IFC)
IF WIRING IS OK