T-M50 / T-M50 ASME Service manual
Ver. 1.05
41
CONFIDENTIAL
Error Code
Diagnosis
Checkpoint
5 Disconnected/damaged O.H.C.F.
(Refer to section 10-12)
Visual inspection: connection/breakage of wires.
Normal: 1 Ωor less between blue & blue
C2
6 Check if hi-limit switch is properly functioning.
121
Error code is
shown after
three failed
attempts at
ignition
7 Disconnected/damaged hi-limit switch. (Refer to section 10-11)
Visual inspection: connection/breakage of wires.
Normal: 1 Ω or less between blue & blue
C1
Error Code
Malfunction description
Cancellation method
Disconnected/short-circuited output thermistor
Turn off the power or water supply
Diagnosis
Checkpoint
311
1 Output thermistor fault
(Refer to section 10-10)
Visual inspection: connection/breakage of wires and/or debris on
thermistor.
Check voltage/resistance between black & black (#12).
Refer to Section 8 for proper range of values.
E2
Error Code
Malfunction description
Cancellation method
Disconnected/short-circuited inlet thermistor
Turn off the power or water supply
Diagnosis
Checkpoint
321
1 Inlet thermistor fault (Refer to section 10-10)
Visual inspection: connection/breakage of wires and/or debris on
thermistor.
Check voltage/resistance between black & black (#42).
Refer to Section 8 for proper range of values.
E3
Error Code
Malfunction description
Cancellation method
Disconnected/short-circuited mixing thermistor
Turn off the power or water supply
Diagnosis
Checkpoint
331
1 Mixing thermistor fault
(Refer to section 10-10)
Visual inspection: connection/breakage of wires and/or debris on
thermistor.
Check voltage/resistance between black & black (#113).
Refer to Section 8 for proper range of values.
E1
