Check Main Board Input Voltage
Connect the unit to power and switch it ON.
Set your multimeter to DC voltage mode.
Measure the voltage across the two pins on the white CN1 terminal on the main board.
✅ Normal: 24 V
⚠️ Abnormal: Below 21 V
Check Water Outlet Valve Output Voltage
With the unit powered ON, press the Water Output button.
Using the multimeter on the DC voltage setting, measure the voltage across the two pins on the yellow J18 terminal on the main board.
✅ Normal: 24 V
⚠️ Abnormal: Below 21 V
Check Water Pump Output Voltage
With the unit powered ON, press the Water Output button.
Using the multimeter on the DC voltage setting, measure the voltage across the two pins on the white CON10 connector on the main board.
✅ Normal: 24 V
⚠️ Abnormal: Below 21 V
Diagnostic Results
If all three voltages are normal, the circuit control section is functioning correctly.
If the first measurement is abnormal → replace the switching power supply.
If the second measurement is abnormal → replace the main board or the water outlet valve.
If the third measurement is abnormal → replace the main board or the water pump.