The easiest way to fix the problem is to watch this video, this video gives you the instructions:
You can also use these steps to solve your problem:
Step 1: - Take the filter out of the water tank - Place the tank without the filter back in the machine - Switch off the machine - Soak the water filter under the tap for 30 seconds
Step 2: - Put the machine back on - Place back the water filter in the water tank
Step 3: - Place a cup under the steam nozzle - Switch the steam dial to the hot water function - The air and water will come out the machine - Switch back the steam dial