Install Instructions
30
NO
NO
NO
HOSE SECURELY 
CONNECTED TO 
CANOPY?
YES
YES
VENT SYSTEM 
FREE OF 
OBSTRUCTIONS?
YES
REPLACE 
BLOWER
CLEAR 
OBSTRUCTIONS
NO
REPLACE HOSE
CONNECT HOSE 
TO CANOPY
NO
HOSE FREE OF 
CRACKS OR 
HOLES?
CONNECT MANOMETER TO 
SUCTION PRESSURE SWITCH 
(SEE FIGURE 24). IS SUCTION 
PRESSURE GREATER THAN:
-0.50 IWC FOR IN3PVNI/IN4PVNI
-0.80 IWC FOR IN5PVNI/IN6PVNI
YES
REPLACE SUCTION PRESSURE 
SWITCH
REPLACE IGNITION MODULE
NO
NO
24 VOLTS AT SUCTION 
PRESSURE SWITCH 
TERMINAL 'NO'?
YES
DISCONNECT IGNITER/SENSOR 
CABLE FROM IGNITION MODULE 
TERMINAL (9). HOLD CABLE 
NEAR TERMINAL. IS SPARK 
PRESENT?
YES
CHECK IGNITER/SENSOR CABLE, GROUND WIRE, CERAMIC 
INSULATOR, AND GAP. CHECK IGNITER/SENSOR CABLE BOOT FOR 
SIGNS OF MELTING OR BUCKLING.
GO TO PAGE 31
NO
DOES BLOWER ENERGIZE?
YES
SPARK PRESENT 
AT PILOT IGNITER/
SENSOR?
YES
TURN OFF GAS SUPPLY.
ADJUST THERMOSTAT TO CALL FOR HEAT.
DID BLOWER OPERATE 
FOR 30 TO 50 SECONDS 
BEFORE SPARK BEGAN?
NO
REPLACE IGNITION 
MODULE
YES
TURN ON GAS SUPPLY.
DOES PILOT BURNER 
LIGHT?
YES
24 VOLTS ACROSS GAS 
VALVE TERMINALS 'PV' 
AND 'MV-PV'?
YES
NO
NO
YES
NO
OPEN VALVES
ALL MANUAL GAS VALVES OPEN?
IS PILOT BURNER ORIFICE 
BLOCKED?
YES
CLEAN OR REPLACE PILOT 
BURNER ORIFICE
NO
NO
24 VOLTS ACROSS IGNITION 
MODULE TERMINALS 'PV' AND 
'MV-PV'?
REPLACE IGNITION 
MODULE
YES
CONTACT GAS 
SUPPLIER
NO
IS GAS SUPPLY PRESSURE 
BETWEEN 4.5 AND 13.5 IWC?
YES
REPAIR OR REPLACE WIRES
REPLACE GAS VALVE
NO
DOES SPARK STOP 
AFTER PILOT IS LIT?
YES
MAIN BURNER LIGHTS?
YES
BOILER CONTROL SYSTEM 
SEQUENCING PROPERLY. 
CHECK DISTRIBUTION 
SYSTEM
24 VOLTS ACROSS GAS 
VALVE TERMINALS 'MV' 
AND 'MV-PV'?
YES
REPLACE GAS VALVE
NO
24 VOLTS ACROSS IGNITION 
MODULE TERMINALS 'MV' AND 
'MV-PV'?
YES
REPAIR OR REPLACE WIRES
NO
REPLACE IGNITION 
MODULE
NO
CHECK CONTINUITY OF IGNITION CABLE AND GROUND WIRE. CLEAN FLAME ROD. 
CHECK ELECTRICAL CONNECTIONS BETWEEN FLAME ROD AND IGNITION MODULE. 
CHECK FOR CRACKED CERAMIC FLAME ROD INSULATOR. CHECK PILOT FLAME
(SEE FIGURE 19). IF CHECKS OKAY, REPLACE IGNITION MODULE.










