Troubleshooting Guide - Schwank S100 Installation & Owner's Manual

21. TROUBLESHOOTING GUIDE

WARNING
SEQUENCE OF EVENTS
APPLY 120 VOLTS
SET THERMOSTAT TO CALL FOR HEAT
COMBUSTION AIR BLOWER STARTS
YES
Air Proving Switch HAS CLOSED
(Blocked Flue Switch REMAINS CLOSED)
24 VOLTS PRESENT AT DSI CONTROL.
YES
SPARK IGNITER / SENSOR
YES
24V TO GAS VALVE
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-
QUIRED REPAIR TO RESTORE 120V
 CHECK FOR 120V FROM RELAY SWITCH
 IF "NO" SWITCHING IS OCURRING......REPLACE
THE RELAY SWITCH
 CHECK FOR OBSTRUCTION IN THE AIR INTAKE
NO
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
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
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
37
S100/ITB I&O Manual
IM101230
RD: JAN 2012
RL: 6B- BA