Fault Finding Chart 3.8 - Rheem 871018 Service Instructions Manual

Fault Finding Chart 3.8

3.8
Fan current detecting
circuit failure
Error code
79 displayed.
Fault Finding Tests 29 – 31
TM002 Integrity 18 & 20L Service Instructions REV: E
D.O.I: 7/11/2007
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Was
Error code 79
displayed prior to
opening the hot
tap?
Test 29 - Diagnostic Point 3
Test 30 and 31 - Diagnostic Point 19
43
Service. All printed copies not bearing this statement in RED are deemed "uncontrolled"
YES
Replace the PCB assembly.
Note: only replace the PCB
NO
assembly if error code 79 is
displayed during combustion.
Components will be "Live"
when
exercise caution
Conduct test with water flowing
Measure the voltage between 9 Brown
and 10 Black on connector B.
Voltage should be between DC2 – 5V
Test 30
Isolate power when
conducting resistance test
Unplug connector L from the PCB and
measure the resistance between 6
Orange and 12 Orange.
Resistance should be between 0.6kilo-
ohms and 2.8kilo-ohms
Test 31
Components will be "Live"
when
exercise caution
Conduct test with water flowing
Measure the voltage between 6 Orange
and 12 Orange on connector L.
Voltage should be between DC70 –
110V
2
conducting tests,
.
conducting tests,