Humidifier tank is full but the base reservoir remains dry; no water flows into base.

Safety first: Unplug before removing the tank.

• Check valve operation: Remove the tank and press the valve pin or button on the cap. Water should flow freely when pressed. If not, clean the valve area under running water.
• Clean valve seal: Disassemble the cap/valve (if designed to be user-serviceable) and rinse out any debris. Ensure the spring and seal are correctly positioned.
• Re-seat tank: Place the tank back on the base, ensuring it is aligned so the valve engages the base post fully.
• Replace valve or cap: If the valve mechanism is broken or the seal is deformed, replace the tank cap/valve assembly.