Service manual

33
Nature of Fault
Examination
Point Diagnostic Point Values Y/N Action
Service
Procedure
2. Measure voltage
between orange (+) and
grey (-) of the water flow
servo connector B
2
.
3. Measure voltage
between brown
~
grey
of water flow servo
connector B
2
(Don not
turn water on)
(See page 42)
4. Measure voltage
between yellow
~
grey
of the water flow servo
connector B
2
(Do not
turn water on)
(See page 42)
11
~
13 VDC
4
~
6 VDC
4
~
6 VDC
Yes
No
Yes
No
Yes
No
Go to 4-3
Replace PCB
Go to D-4-4
Replace water
flow servo
sensor.
Normal
Replace water
flow servo
sensor.
IGE – 2
IGE – 3
IGE – 3
E. Anti-frost
heater does not
work.
1. check anti-frost
heater.
1. # Disconnected
connector F
4
and F
5
measure resistance
across each of the
heating elements. (white
wires)
(See page 43)
2. # Read resistance of
the heating element that
is mounted on the front
of the heat exchanger.
(white wires)
(See page 43)
3. Read resistance of
heating elements on the
heat exchanger outlet
hot water line.
(See pag
e 43)
348
~
375Ω
100
~
11 0 Ω
33
~
39Ω
Yes
No
Yes
No
Yes
No
Go to E-1-2
Replace Anti-
frost sensing
switch.
Go to E-2
Replace Anti-
frost heater
that is
defective.
Go to E-2
Replace Anti-
frost heater
that is
defective.
2. Chec
k frost
sensing swit
c
h
# Disconnect connector
F
2
and measure across
the bi-metal sensing
switch located on the
upper right hand of the
heat exchanger. check
this switch at
t
emperatures below 37
°F. You can place an ice
cube against the switch
to activate it.
(See page 43)
Is r
esistance <1Ω
af
t
er appl
ying ice to
this switch for five
minut
es?
Yes
No
Chec
k wiring
R
eplace Anti-
frost sensing
swit
c
h.
VI - TROUBLESHOOTING (cont.)
Troubleshooting Flow Chart
BEFORE CARRYING OUT CHECKS MARKED WITH
A # SIGN, DISCONNECT THE POWER SUPPLY.