Sandra Pupatello is taking over as chair of Hydro One as it deals with a serious overbilling fiasco.

Pupatello joined the crown utility's board in November and replaces James Arnett who held the post since 2008.

Hydro One has been under the microscope of the Ontario ombudsman since Andre Marin received a slew of customer complaints including billing errors that reached as high as $20,000.

The appointment takes places on April 1.

Pupatello will remain on as CEO of the Windsor-Essex Economic Development Corporation.