Abstract: Disclosed is a method and apparatus for preventing the formation of blisters in an electrically-heated forehearth that utilizes submerged electrodes connected to either a single or plural phase alternating current source. The electrodes are arranged so that Joule effect heating is effected by passing alternating current through the molten glass with the center tap of the secondary of the power transformer being connected to the positive side of a Direct Current source through a filter, while the negative side of the DC source is connected to a counter electrode, immersed in the glass at a point upstream of the forehearth.With this physical arrangement, the formation of blisters due to free electrons migrating to and collecting on some of the electrodes that are at different potentials than the others is prevented.