Overtime, the seal on the fan unit can become hardened due to residue build up which will weaken the air tight seal between the fan unit and the boiling chamber. This can cause it to leak or steam to escape.
Changing the seal with a new one will resolve this.
We also recommend cleaning your seal every 3-6 months (or whenever it begins to gather residue/harden).
You can do this using warm water and a dish sponge to loosen and remove hardened residue that has accumulated on the seal.
This can extend the the time needed before replacing the seal.