Why is there a smell coming out of my dehumidifier?

This is caused by the Zeolite desiccant material and is not a sign that the dehumidifier is faulty, nor is it harmful to humans or pets.

The smell comes from the Zeolite, which absorbs odours from items like cigarettes, cosmetics, hair sprays, building materials and new furniture. 

When the desiccant is heated, the smell may get discharged back into the room. This smell has been described as being like a burning smell or a sour smell.

If you prefer, you can put the dehumidifier in the garage and run it on "laundry" mode there to get rid of the smell to the outside of the house.