Service Manual

With flame sensor Disconnected
f
rom ignition module, check
continuity to ground.
Is there continuity to ground?
N
Y
Service Procedure EF-VIII
Flame Sensor Testing and Replacement
Flame Sensor Testing Procedure
Refer to illustration below, is there
a
minimum of 1 micro amp during
1.5 second flame proving period?
Y
N
Is flame sensor free
of oxidation?
Clean or replace
flame sensor.
(see “Flame Sensor
Replacement
Procedure”)
N
Is ceramic of flame
sensor cracked?
Replace flame sensor.
(see “Flame Sensor
Replacement
Procedure”)
Y
N
F
lame sensing circuit OK
Y
Refer to ignition module/control board
illustration.(24 volts should maintain beyond the
1.5 second flame proving period.)
H
ot Surface Ignition Models:
I
s there 24 volts AC at locations P3(2) & P3(5)?
D
irect Spark Ignition Models:
Is there 24VAC between P5(5) and P5(8)?
Y
N
Call for
technical support
R
eplace flame sensor with
gasket
and/or wire lead.
(see “Flame Sensor
Replacement Procedure”)
Remove flame sensor from water heater.
C
heck continuity from tip of flame sensor
to end of wire lead.
Is there continuity?
N
Y
WARNING
1
20 volt potential exposure. Use caution
m
aking voltage checks to avoid
personal injury. Flame sensor may be
too hot to handle, take necessary
precautions
62
Flame
sensor
terminal
Volt meter set to
Micro amps setting
(
ȝA)
Meter probe
Meter probe
Flame sensor
terminal on
control board.
Flame sensor
terminal
123
8
6
5
4
3
1
12
1
4
1
3
3
2
1
1
5
3
P2P4P5 P7P3
CONTROL BOARD
P10P9J1
Volt meter set to
Micro amps setting
(
ȝA)
Meter
probe
Meter
probe
Flame sensor
terminal on
ignition module.
HOT SURFACE IGNITION MODELS
DIRECT SPARK IGNITION MODELS
62