Schwank STSp-USA - Manual (Page 28)

SP-MSTP-AU-05A
STS-p Manual
RD: DEC, 2003
RL: 5
KH
UA SERIES: TROUBLESHOOTING GUIDE HONEYWELL S87J1034 120V THERMOSTAT
PLUG INTO 115 VOLTS (GREEN LIGHT IS ON)
COMBUSTION AIR BLOWER STARTS
ON 24V OPTION ONLY:
CHECK FOR II5V FROM SWITCHING RELAY.
CHECK 24V SIDE OF RELAY VOLTAGE.
CHECK 115V LINE SIDE OF RELAY VOLTAGE.
CHECK OPERATION OF BOTH CIRCUITS.
IF NO SWITCHING IS TAKING PLACE.........
......REPLACE THE SWITCHING RELAY
YES
NO
CHECK IF 115 VOLTS PRESENT AT BLOWER
IF SO............REPLACE DEFECTIVE BLOWER
A.P.S. HAS CLOSED (B.F.S. IS CLOSED)
24 VOLTS PRESENT AT DSI CONTROL
AMBER LIGHT IS ON
NO
CHECK AIR INTAKE AND FLUE ARE NOT OB-
STRUCTED.
CHECK PRESSURE TUBE 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 SWITCHES.
SPARK AT IGNITER / SENSOR.
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 SO
TAKE PROTECTIVE ACTION TO SHIELD CABLE
AND BOOT FROM EXCESSIVE TEMPERATURES.
CHECK CERAMIC INSULATOR AND CAP.
SPARK GAP SETTING IS 3/16”. (ADJUST BY
MOVING THE GROUND PRONG ONLY.)
PERFORM IGNITION LEAD TEST (SEE SPARK
IGNITION CIRCUIT INSTRUCTIONS ON PAGE 28)
GOOD SPARK .....................REPLACE IGNITER
NO SPARK /OR WEAK .......REPLACE CONTROL
cont’d
Page 24
SET THERMOSTAT TO CALL FOR HEAT
ON 24V OPTION ONLY:
THE SWITCHING RELAY ENERGIZES,
SENDING 115 VOLTS TO THE BLOWER
YES
NO
24V TO GAS VALVE
(RED LIGHT IS ON)
YES