Schwank STSV - Manual (Page 37)

37
STV-JZ I&O Manual
IM090512
RD: MAY 2009
RL: 08A- BA
 CHECK 120V SUPPLY TO RELAY SWITCH
 IF ELECTRICAL SUPPLY PROBLEM …. MAKE RE-
QUIRED REPAIR TO RESTORE 120V
 CHECK FOR 120V FROM RELAY SWITCH
 IF “NO” SWITCHING IS OCURRING......REPLACE
THE RELAY SWITCH
SET THERMOSTAT TO CALL FOR HEAT
APPLY 120 VOLTS - GREEN LIGHT IS ON
 CHECK IF 120 VOLTS PRESENT AT VACUUM
PUMP
 IF “YES”.....CHECK FOR PHYSICAL BLOCKAGE OF
THE PUMP; REPLACE DEFECTIVE VACUUM
PUMP
VACUUM PUMP STARTS
A.P.S. HAS CLOSED (B.F.S. IS CLOSED)
24 VOLTS PRESENT AT DSI CONTROL.
AMBER LIGHT IS ON
 CHECK FOR OBSTRUCTION IN THE AIR INTAKE
AND FLUE
 CHECK TUBING TO SWITCHES IS CONNECTED
AND NOT BLOCKED OR KINKED
 CHECK IF AIR PROVING SWITCH IS CLOSING
WHEN BLOWER IS RUNNING
 CHECK AIR PRESSURE WITH MANOMETER
 REPLACE ANY DEFECTIVE SWITCH
 CHECK DSI CONTROL FUSE FOR CONTINUITY
 VISIBLY CHECK IF IGNITER IS SHORTING OUT
 CHECK GROUND WIRING
 REMOVE AND INSPECT IGNITER AND LEAD
 CHECK BOOT OF THE IGNITION CABLE FOR SIGNS
OF MELTING OR OVERHEATING
 IF “YES” ... TAKE PROTECTIVE ACTION TO SHIELD
CABLE AND BOOT FROM EXCESSIVE TEMPERA-
TURE; REPLACE ANY DEFECTIVE COMPONENT
 CHECK CERAMIC INSULATOR AND CAP
 CHECK SPARK GAP SETTING IS 3/16” (ADJUST BY
MOVING THE GROUND PRONG ONLY)
 PERFORM IGNITION LEAD TEST (See SPARK IGNI-
TION CIRCUIT INSTRUCTIONS—Section 22)
 GOOD SPARK.....REPLACE IGNITER
 NO SPARK/OR WEAK.....REPLACE CONTROL
SPARK IGNITER / SENSOR
24V TO GAS VALVE - RED LIGHT IS ON
CONTINUED
SEQUENCE OF EVENTS
21. TROUBLESHOOTING GUIDE
NO
YES
WARN-
Improper adjustment, alteration, service or maintenance can
cause property damage, injury or death. This heater must be
installed and serviced only by a trained gas service technician
YES
YES
NO
NO
 CHECK 24V SUPPLY TO RELAY SWITCH
NO