The answer to 'why is my dehumidifier high energy bills' is that a dehumidifier can use a significant amount of electricity, especially if it's running constantly or the unit is inefficient. Common causes include an oversized dehumidifier for the space, poor insulation or air leaks in the home, and the dehumidifier running at a higher capacity than needed.
Symptoms of high energy bills from a dehumidifier include the unit running continuously, high humidity levels despite the dehumidifier running, and a spike in your electricity usage. Solutions include ensuring the dehumidifier is the right size for the space, improving insulation and sealing air leaks, and adjusting the dehumidifier settings to the minimum needed to maintain comfort.