Nine firefighters attended the property, near Longueville Manor in St Saviour, but the fire was out before they arrived.
In a tweet, the Fire and Rescue Service said: ‘Please remember your hob isn’t an extension of the work top.’
No one was injured in the incident.
Station commander Mike Baudains said: ‘It is not the first time something like this has happened. ‘These types of hobs can easily be switched on, so it is important that people don’t leave items on top of them.
