11 L smart tower ultrasonic humidifier with a water-pump feed system, app/touch/voice control, Auto Mode, and exact troubleshooting for pump noise, leaks, and no-mist complaints.
Choose the observed symptom, light, code, app state, or output problem.
The HM735S no-mist path is unusually specific because the tower uses a pump-fed water path. Dreo says to check the air inlet, reservoir water level, room ventilation, Auto Mode target, atomizer scale, and then allow about 15 seconds for the pump to move water after the inlet tank has run dry.
For an HM735S leak, first dry the unit and identify where fresh water appears. Dreo’s current model FAQ points to a cracked tank, the outlet-valve silicone sealing ring, room humidity above about 60%, excess water around the unit, movement of a filled humidifier, and level placement.
A short, slight pump sound can be normal on the HM735S because this model actively transfers water. Dreo specifically says a brief noise when the pump starts is normal; the useful diagnosis is whether the sound is short and mild or becomes loud, prolonged, grinding, or accompanied by poor water transfer.