It is normal, because the instant electric water heater has the function of preventing dry burning. Even if it is powered on, the water heater will not work when there is no water, but the display screen will stay on, which will not cause any danger.
Although being in this state for a long time may affect the life of the screen, in general, the service life of the instantaneous electric water heater is 5-8 years, and it can even be used for a longer time.
Therefore, the instantaneous electric water heater is safer than the storage electric water heater.