Troubleshooting Guide - Schwank STS-JZ Installation & Owner's Manual

21. TROUBLESHOOTING GUIDE

WARN-
SEQUENCE OF EVENTS
APPLY 120 VOLTS - GREEN LIGHT IS ON
SET THERMOSTAT TO CALL FOR HEAT
COMBUSTION AIR BLOWER STARTS
YES
A.P.S. HAS CLOSED (B.F.S. IS CLOSED)
24 VOLTS PRESENT AT DSI CONTROL.
AMBER LIGHT IS ON
YES
SPARK IGNITER / SENSOR
YES
24V TO GAS VALVE - RED LIGHT IS ON
CONTINUED
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
 CHECK IF 120 VOLTS PRESENT AT BLOWER
NO
 IF "YES".....REPLACE DEFECTIVE BLOWER
NO
 CHECK 24V SUPPLY TO RELAY SWITCH
 CHECK 120V SUPPLY TO RELAY SWITCH
 IF ELECTRICAL SUPPLY PROBLEM .... MAKE RE-
 CHECK FOR 120V FROM RELAY SWITCH
 IF "NO" SWITCHING IS OCURRING......REPLACE
 CHECK FOR OBSTRUCTION IN THE AIR INTAKE
NO
 CHECK TUBING TO SWITCHES IS CONNECTED
 CHECK IF AIR PROVING SWITCH IS CLOSING
 CHECK AIR PRESSURE WITH MANOMETER
 REPLACE ANY DEFECTIVE SWITCH
 CHECK DSI CONTROL FUSE FOR CONTINUITY
NO
 VISIBLY CHECK IF IGNITER IS SHORTING OUT
 CHECK GROUND WIRING
 REMOVE AND INSPECT IGNITER AND LEAD
 CHECK BOOT OF THE IGNITION CABLE FOR SIGNS
 IF "YES" ... TAKE PROTECTIVE ACTION TO SHIELD
 CHECK CERAMIC INSULATOR AND CAP
 CHECK SPARK GAP SETTING IS 3/16" (ADJUST BY
 PERFORM IGNITION LEAD TEST (See SPARK IGNI-
 GOOD SPARK.....REPLACE IGNITER
 NO SPARK/OR WEAK.....REPLACE CONTROL
41
QUIRED REPAIR TO RESTORE 120V
THE RELAY SWITCH
AND FLUE
AND NOT BLOCKED OR KINKED
WHEN BLOWER IS RUNNING
OF MELTING OR OVERHEATING
CABLE AND BOOT FROM EXCESSIVE TEMPERA-
TURE; REPLACE ANY DEFECTIVE COMPONENT
MOVING THE GROUND PRONG ONLY)
TION CIRCUIT INSTRUCTIONS—Section 22)
STS-JZ / IQ I&O Manual
IM101220
RD: MAY 2012
RL: 14D - BA