t_
h_
P.
m
o
0
O"
3"
in
o
o
_Q
.=.
Q.
0
_t
Z
o
PF
"n
o
=.
DO BURNERS
FUNCTION?
NO
BOESIGNm_R WARM YES
DP AND GL_V RED?
(INTERMffTENT_
Is FAN RUNNING?
NO
_f
SEE TABLE 8 ]
1) CHECK FOR 24VAC AT PRESSURE
SWITCH ',NO" TERMINAL TO GROUND.
IF NO VOLTAGE, CHECK FOR:
. BLOCKED OR CRACKED SUCTION
TUBING.
. FAN NOT GENERATING ADEQUATE
SUCTION PRESSURE.
• DEFE_rlVE PRESSURE SWITCH.
2) CHECK FOR 2/VAC AT p4222 RELAy
BLUE WIPES TO GROUND:
- IF NO VOLTAGE AT EITHER BL WIRES.
CHECK FOR BROKEN/LOOSE WIRE.
. IF NO VOLTAGE AT ONL¥ ONE BL WlRE.
CHECK FOR 120VAC BETWEEN R4222
RELAy BLACK AND WHITE W1RES. IF
SO. RELAy IS DEFECTIVE.
3) CHECK FOR 24VAC AT FLAME ROLL*OUT
BW1TCH, IF SWITCH IS BLOWN. CORRECT
CAUSE OF ROLL*OUT BEFORE
REPLACING SWITCH.
FOR NEATI • TURN OFF GAS SUPPLY
• ASSURE GAS VALVE SWITCH IS
IN "ON" pOSITION
• DISCONNECT SYSTEM CONTROL
HARNESS
• SET THERMOSTAT TO CALL
S CNEC'ORPRDPORVOLTAGE0NECK
AT CONTROL HARNESS {SEE INSET • LINE VOLTAGE pOWER
A)* VOLTAGE SHOULD BE 24V * LOW VOLTAGE TRANSFORMER
BETWEEN THERMOSTAT AND • LIMIT CONTROLLER
24V COMMON, AND 24V BETWEEN • THERMOSTAT
24V COMMON AND 24V HOT. •WIRING
YES
UNPLUG pILOT BURNER CABLE.
I IGN_'rER WARMS UP AND _ MEASURE VOLTAGE AT GAS VALVE
GLOWS RED HSI ELEMENT OUTPUT (SEE INSET B)
24V NOMINAL
+ YES
] IREPLACEGNOE PLAMERODASSSMBL¥1
RECONNECT PILOT BURN[R CABLE
1[ YES
l _'ORRECT
THERMOSTAT
pI_BLEM
JUMPERTHERMOSTAT NO_ REpLACELIMITCONTROL
AT CONNECTIONS CHEC K FOR 120VAC HIGH LIMIT CONTRO L.IF
"G" AND "y" ON R8285. pOWER ATONETERMINAL BUT NOTBOTH,
DOES BOILER RUN?
•CHECK FOR 24VAC AT PRESSURE SWITCH
J TERMINALS "C" AND "N C" TO GROUND:
OlF VOLTAGE AT "N C" BUT NOT 'C",
PRESSURE swFrcH IS STUCK IN
RUNNING POSITED N. CHECK FOR BLOCKED
AIR TUBE. IF OKAy, REPLACE pRESSURE
S'01_TCH,
elF NO VOLTAGE AT EITHER PRESSURE
SWITCH TERMINAL "C" OR "NO _ TO
GROUND, CHECK FOR 120VAC INCOMING
pOWER INSIDE JUNCTION BOX, IF PROPER
INCOMING POWER, REPLACE R8285.
YES
L
I • TURN ON GAS SUPPLY
• piLOT BURNER LIGHTS
YES
L
IMANV'LVEOPEN AND
MAIN BURNER UGHTS
I YES
L SYSTEM iS OKAY l
INSET A
END VIEW OF
24 VOLT CO NTROL
TA HARNESS
THERMOS T CONNECTOR
VOLTS
24 VOLT V T
COMMO 24 GL
VOLTS HOT
CHECK FOR DAMAGED OR MISSING
TERMINALS IN CONNECTOR
INSET B
• CHECK THAT PILOT GAS IS FLOWING.
WAIT TO ASSURE PILOT GAS TUBING
IS PURGED.
_ YES
• MEASURE VOLTAGE BETWEEN 24V
HOT AND 24v COMMON LEADS TO GAS
VALVE. MUST MEASURE AT LEAST
19+_ VAG WITH IGNITER pOWERED.
SEE INSET A TO IDENTIFY PROPER
LEAD. THIS CHECK MUST BE DONE
WITH THE GAS VALVE CONNECTED
AND IGNITER pOWERED.
_ YES
REPLACE GAS VALVE ]
lREDONNECTP'LOTBDROOR1CABLE
REPLACE IGNITER/FLAME ROD ASSEMBLY I
REPLACEIGNITER/FLAME ROD ASSEMBLY J
• CHECK 1"HAT PILOT FLAME MAKES _1 iOGOOD CONTACT WITH PILOT BURNER
CYCLE THER STAT OFF AND _ACK ON I
FLAME ROD
• CHECK FOR GOOD ELECTRICAL
CONNECTION THROUGH THE PILOT
TOO,NG I I I
• IF BOTH OF THE ABOVE ARE GOOD, IF MAIN BURNERS DO NOT LIGHT,
REPLACE iGNITER/FLAME ROD REPLACE GAS VALVE
ASSEMBLY.
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