Please try the following, which should rectify the problem:
- Ensure the steam function has been selected on the control panel.
- Open the steam dial fully.
- Check the milk nozzle(s) are completely clean and free of milk debris. (There will be either one or two removable milk nozzles depending on your machine). These should always be cleaned after each milk delivery session.
- Check both o-rings are intact on the milk frother.
These steps should rectify the problem. However if you are still experiencing an issue please take your machine to your nearest repair centre for inspection. If your product is under guarantee please contact Delonghi Customer Experience.