All installations and services must be performed by qualified service personnel.
IS INDUCER RUNNING
ON LOW SPEED?
YES
DOES THE HOT
SURFACE IGNITOR
ENERGIZE AND GLOW?
YES
NO
NO
CHECK CONTACTS ON LOW FIRE PRESSURE SWITCH AND FOR BLOCKAGE IN FLUE. IF OK, REPLACE DUAL PRESSURE SWITCH.
IS THERE VOLTAGE ACROSS
HOT SURFACE IGNITOR
TERMINALS "IGN" & "IGN N" AT THE
YES |
CHECK WIRING TO HOT
SURFACE IGNITOR AND
IF OK, REPLACE HOT
SURFACE IGNITOR
ASSEMBLY
REPLACE THE
|
| YES | |
|
|
| |
| IS THE HIGH LIMIT, | ||
NO | |||
AUX LIMIT ON | |||
| |||
| (CDX MODELS) | ||
| SWITCHES CLOSED? |
NO |
IF HIGH LIMIT OR
AUX LIMIT OPEN CHECK
FOR RESTRICTED
FILTERS OR DUCT WORK IF
AFTER HOT SURFACE
IGNITOR
DOES GAS VALVE OPEN?
YES |
AFTER GAS VALVE
OPENS, DO THE
BURNERS IGNITE?
NO
NO
| CHECK ACROSS "MVL" AND |
| ||
| "MV COM" TERMINALS ON |
| ||
| NO | |||
| VOLTS DURING THE 4 SECOND | |||
|
| |||
| FLAME PROVING PERIOD |
| ||
| AFTER IGNITOR |
| ||
| IS THERE 24 VOLTS? |
| ||
|
|
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|
|
|
| YES |
| |
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IS COLLECTOR BOX | NO |
PRESSURE SWITCH CLOSED?
YES |
CHECK WIRING TO GAS
VALVE AND IF OK,
REPLACE GAS VALVE.
CHECK FOR PROPER LINE
AND MANIFOLD PRESSURE.
REFERENCE GAS PRESSURE
CHART PAGE 31.
REPLACE THE
CHECK DRAIN FOR BLOCKAGE WATER TRAPPED IN HOSE, REPLACE SWITCH.
YES
OK
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