Ca series: troubleshooting guide – Schwank STSp-WP User Manual

Page 28

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SP-MSWP-BX-09A

STSp-WP Manual

RD: MAY 2004

RL: 9

KH

Page 24

ON 24V OPTION ONLY:
THE SWITCHING RELAY ENERGIZES,
SENDING 115 VOLTS TO THE BLOWER

21. CA SERIES: TROUBLESHOOTING GUIDE

APPLY 115 VOLTS

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

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.

• CHECK SPARK GAP SETTING IS 3/16”. (ADJUST

BY MOVING THE GROUND PRONG ONLY.)


PERFORM IGNITION LEAD TEST (SEE SPARK

IGNITION CIRCUIT INSTRUCTIONS ON PAGE 27)
GOOD SPARK .....................REPLACE IGNITER
NO SPARK /OR WEAK .......REPLACE CONTROL

cont’d

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

YES

APPLY 115 VOLTS—GREEN LIGHT IS ON

A.P.S. HAS CLOSED (B.F.S. IS CLOSED)
24 VOLTS PRESENT AT DSI CONTROL.

AMBER LIGHT IS ON

24V TO GAS VALVE - RED LIGHT IS ON

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