Rheem 871018 Service Instructions Manual page 37

Fault Finding Tests 5 – 8
Unplug connector B from the PCB and measure
the resistance of the Over Heat Limiter Assembly.
Resistance should be between 50kilo-ohms and
500 kilo-ohms.
Isolate power when conducting resistance tests. "Live" components
present during voltage tests, exercise caution
Use an insulated tool when operating the
DIP switch or MIN and MAX buttons.
TM031 Integrity 18, 20, 24, 26L Service Instructions REV: B
D.O.I: February 2008
This document is stored and maintained electronically by
Isolate power before removing connector plugs
Test 5
Test 8 – Diagnostic points 5, 6, 7 & 8
Service. All printed copies not bearing this statement in RED are deemed "uncontrolled"
Unplug connector K from the PCB. Restore
power and check if error code 79 is displayed
within 30 seconds.
Test 7
Maintenance
Error
Display
code
Code
3y: Water
31 Inlet
Thermistor
4y:
Combustion
32
Chamber
Thermistor
5y: Hot
33 Water Outlet
Thermistor
2y: Ambient
34 Air
Thermistor
37
Test 6
Diag Measured
Test Point
Point Value
6 Yellow
5
7 Black
20ºC –
10.3 kilo-
5 White ohms
6
40ºC –
7 Black
4.9 kilo-
ohms
4 Red
7
7 Black
25ºC –
5.0 kilo-
3 Blue ohms
8
5ºC –
7 Black
12.7 kilo-
ohms