Fault codes – Rinnai RHFE-750ETR User Manual
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Rinnai Corporation RHFE-750ETR
Fault
Codes
If there is a malfunction the appliance may shut down as a safety precaution and display a fault code to assist in 
diagnosing the problem. The fault code will flash in the Fault Code Display window and the Operation Indicator 
will flash green. 
Code
Fault
Remedy
11 Ignition
failure
Confirm that the gas supply is turned on. Switch appliance to 
STANDBY and then ON again. If ignition failure continues 
then a Service call is required. 
12 Incomplete
combustion
Service
call
14
Filter blocked or Overheat
Clean filters 
If overheating continues then a service call is required to 
determine the cause. 
Thermal fuse; a qualified service technician must replace the 
fuse following the procedure below. 
16 Room
overheat
The temperature has reached 104° F (40° C). Turn the 
appliance off or engage the AUTO OFF function to prevent the 
display of flame. See AUTO OFF section. 
31
Room temperature sensor faulty
Service call
32
Overheat temperature sensor faulty
Service call
53
Spark sensor faulty Service
call
61
Fan motor faulty
Service call
71 Solenoids
faulty
Service
call
72
Flame detection circuit fault
Service call
73 Communication
fault
Service
call
99
Flue block
Check around flue terminal for obstructions to air flow
The cause of the overheat condition needs to be 
determined and remedied before replacing the 
thermal fuse. 
A qualified service technician needs to:
1. Disconnect the appliance from the power supply.
2. Remove the right hand side panel to allow access
to the gas control and main PCB.
3. Unplug the thermal fuse harness (including the
control plug for the POV on the gas control) and 
unscrew thermal fuse. 
4. Re-assemble with replacement thermal fuse.
PCB
POV
Thermal Fuse
Replacement of Thermal Fuse
