A surge protection device includes a gas discharge tube surge protector connected between a Tip line and a Ring line, and further includes solid state heat-generating resistive elements in the Tip and Ring lines, and thermally-responsive sneak current grounding switches in the Tip and Ring lines that have an untripped position connecting Tip and Ring line terminals of the surge protector respectively to the Tip and Ring line resistive elements, and a tripped position in which they ground the Tip and Ring line terminals. The switches are switched to their tripped position in response to the heat generated in the resistive elements as a consequence of current passing through them that exceeds a predetermined current level. A surge suppression element is connected in parallel with each of the resistive elements. The resistive elements are preferably carbon film resistors, and the surge suppression elements are preferably transient voltage suppression diodes.