Specifications

TM040 16, 18 & 20L Continuous Flow Gas Water Heater Service Instructions
D.O.I: 2/06/2009
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43
Fault Finding Tests 17 & 18
Tests 17 and 18 – Diagnostic Point 4
12VDC JAPAN
G5NB-1A4 OMRON
G
F
6 - White
4 - Blue
3 - Red
1 - Yellow
OMRON G5NB-1A4
12VDC JAPAN 12VDC JAPAN
G5NB-1A4 OMRON OMRON G5NB-1A4
12VDC JAPAN
JAPAN
Conduct test with water flowing
Using a multimeter set on the DC volts scale, measure
the voltage at connector F whilst plugged into PCB.
Test
Check Point
Measured Value
17
4 Blue – 6 White
DC120 - 160V
3 Red – 4 Blue
DC12 - 18V
18
1 Yellow – 4 Blue
DC4 - 10V
(or measurement by pulse
counter of not less than
4800 pulses per minute)
Error Code 65
Error Code 65
Isolate power to unit for 10
seconds and restore power
Is the voltage of water control
motor normal?
TEST 21
Replace the PCBNO
Set temperature 48
o
C or below
Set temperature above 48
o
C
Is the resistance of the
bypass solenoid correct?
TEST 19
Replace water body assemblyNO
Is there voltage at bypass
solenoid?
TEST 20
Replace the PCBNO
YES
Is the voltage of water control
motor normal during use?
TEST 22
Replace the PCBNO
YES
Replace water body assembly
YES
YES