A drain-back valve is provided for draining a submersible pump system in a water well. The drain-back valve includes, for example, a body, an end cap and a plunger assembly. The end cap is inserted into one end of the body includes at least one port that is in fluid communication with an interior passageway of the body. The plunger assembly engages the opposing end of the body. When closed, the plunger assembly prevents water from flowing into the interior passageway of the body. The drain-back valve is activated or opened by dropping a weight into a riser or drop pipe. The weight strikes the plunger assembly and opens the drain-back valve to allow water to flow through the body and out the end cap. This allows well water in the drop or riser pipe to drain back into the water well. With this water drained from the drop or riser pipe, a pump service personnel on the ground surface is able to pull up the pump without the water weight that was in the drop or riser pipe. After servicing and before re-installation back into the well, the drain-back valve is reset to its normally closed position.