①
541
711
141
321
311
331
701
031
721
651
541
661
611
111
121
510
711
321
311
331
661
651
701
991
141
Circuit board for valve D.E.F Failure
Valve B failure
Valve C failure
Circuit board
Abnormal High Temp.
High-limit switch
YES
YES
YES
YES
YES
YES
YES
Valve A
Open limit On
Valve C
Open limit On
Valve A
Open limit On
Pre-check
Normal
Flow Sensor
>=0.75 GPM
Valve C
Close limit Off
Set Temperature
<=140F
Power On
Operation Switch ON
Faucet open
NO
(After 18 sec.)
NO
(After 18 sec.)
NO
(After 18 sec.)
NO
(After 18 sec.)
NO
NO
NO
(After 18 sec.)
NO
Valve B
Open limit On
⑥
⑤
*1
*2
*3
Abnormal Burning
*5
*6
YES
②
②
①
⑰
④
⑧
③
④
⑱
(After 35 sec.)
Open Valve A
Open Valve B
Open Valve C
Display:
Display: Priority
Control Valve B
Open Valve B
Open Valve A
611
*13
*4
Valve A failure
High-limit switch off
Open Short:
Inlet Temp. Thermistor
Open Short:
Output Temp. Thermistor
Open Short:
Mixing Temp. Thermistor
Circuit board failure
Mismatched gas
Flame failure
Valve C failure
Abnormal fan rotation
Ignite failure
Lost flame
Valve C failure
Valve B failure
Valve H failure
Gas valve circuit
board failure
Open Short:
Inlet Temp. Thermistor
Open Short:
Output Temp. Thermistor
Open Short:
Mixing Temp. Thermistor
Fan off
Faucet close
Flow sensor off
Operation switch off
Power off
All display off
Maintenance
Fan off
Valve H off
Valve D off
Valve G off
Valve E off
Valve F off
B
MOBIUS
Water Heater
Model T-M1
Trouble Shooting
Diagnose
Flow - Chart
Start
C