Dunkirk Q90-50 - Page 56

Troubleshooting Chart 5
_r
DOES MAIN BURNER
RUN UNTIL CALL FOR
HEAT ENDS OR HI
LIMIT AQUASTAT
CONTACTS OPEN?
CHART 4 CHART 4
YES l- YES
POSSIBLY MIXTURE TOO LEAN!
CHECK GAS LINES DOWNSTREAM OF GAS
VALVE FOR BLOCKAGE.
ARE GAS LINES CLEAR?
IS GASNENTURI VALVE CORRECT SIZE?
SEE REPAIR PARTS DIAGRAM.
,_IFYES
POSSIBLY MIXTURE TOO RICH!
CHECK FLUE PASSAGES IN BOILER PER
"MAINTENANCE AND CLEANING". ARE
FLUE PASSAGES IN BOILER CLEAN?
CHECK MIXERAND BURNER FOR
BLOCKAGE PER MAINTENANCE AND
CLEANING INSTRUCTIONS. ARE AIR
PASSAGES IN MIXERAND BURNER
CLEAN?
4,
CHECK AIR ORIFICE AT BURNER INLET
FOR CORRECT SIZE. SEE REPAIR PARTS
DIAGRAM. IS ORIFICE CORRECT SIZE?
NO#1
NO #2
NO #3
7
* IF THE ANSWER IS NO.
CHOOSE THE APPROPRIATE
PATH (#1, #2, OR #3) BASED ON
SYMPTOMS SHOWN.
RUNS SMOOTHLY FOR ABOUT 6
SECONDS THEN SHUTS OFF.
INDICATES POOR FLAME SIGNAL.
CHECK IGNITER/SENSOR
POSITION. TIP SHOULD BE
SLANTED TOWARDS BURNER
CLEAN/REPLACE GAS LINES.
BE SURE TO USE CORRECT GAS/VENTURI VALVE SIZE
CLEAN BOILER FLUE PASSAGES PER MAINTENANCE
AND CLEANING INSTRUCTIONS
CLEAN MIXERAND BURNER PER MAINTENANCE AND
CLEAN NG NSTRUCTONS
,_YES
CHECK FLAME SIGNAL >0.6uA?
CONSULT BOILER MFGR. FOR
SPECIFIC INSTRUCTIONS.
REQUIRES SPECIAL TOOLS.
,4r YES
REPLACE IBC
REPLACE BURNER
RESTORE
IGNITER/SENSOR
TO CORRECT POSITION
DO NOT RELOCATE.
OXIDE COATING ON
IGNITER PREVENTING
FLAME SIGNAL.
REPLACE
IGNITER/SENOR.
CHART 6 CHART 6 CHART 6