
TM090 12-26 Series II CFGWH Service Instructions
REV AB
– Issued February 2019
This document is stored and maintained electronically by Rheem Technical Support. All printed copies
are deemed “uncontrolled”
44
Fault Finding Charts 3.3 & 3.5
YES
Flame failure
NO
NO
Purge failure
3.3
Adjust maximum and minimum
burner pressures.
YES
YES
3.5
For error code 80 or 81 replace
the lower burner assembly.
For error code 51 replace the
proportional gas flow regulating
valve.
NO
Replace the PCB assembly.
NO
YES
Replace flame sensors
YES
3.6
Clean the heat exchanger,
combustion chamber, fan and air
intake. For error code 99 reset the
PCB by following the procedure in
the section on ‘Error Codes’.
NO
YES
3.2
Abnormal combustion
YES
NO
NO
Replace the relevant thermistor.
Adjust maximum and minimum
burner pressures.
YES
NO
*Combustion chamber
and hot water outlet
thermistors
Thermistor connections crossed.
Reposition thermistor connections
correctly.
Test 6 & 7
Very high temperature
Thermistor
connection failure
Is error
code 12
displayed?
Are the
max and min
burner pressures
correct?
Is error
code 10 or 99
displayed?
NO
Is error
code 15
displayed?
*Is the resistance
of the thermistors
correct?
NO
Are the maximum
and minimum
burner pressures
correct?
Is the PGFR valve
operating
normally?
YES
Test and replace if faulty
NO
Test 10
Is error
code 35
displayed?
Is error
code 81
displayed?
Does the
flame extinguish
completely?
Is the
flame detection
maintenance
information
indicating 00?
YES