Possible Reasons:
If the screen displays as "- -", and the machine doesn't heat up at the same time. It is possibly because of the following issues: The machine is in the "stand by" state.
Solutions:
Power on the machine:
Long-press the power key for 2–3 seconds to turn on the device, then you can see a "fire" icon. It means the machine is heating up.
If you make sure the machine is powered on, but still not heat up.
1. Make sure the wipe places in the machine correctly. Check if the spring can hold the wet wipes in the correct position.
2. use +/- to adjust the heating temperature.
3. Wait for the machine preheating for 10-15 mins.
4. If it still not works, you can power off for about 30 seconds and then restart.