Shallow Well Pumps like the Model 1900 Stainless Steel Pitcher Pump are subject to freezing because the piston and foot valve are both located in the body of the pump which is above ground and exposed to the weather. With a normal piston / foot valve system, water is trapped between the foot valve and the piston. The only way to remove that water is by removing the piston assembly and draining the pump.
Bison Pumps has developed the Drain Back Feature for customers who need to winterize a pump that is exposed to freezing conditions. The Drain Back Feature is a standard Model 1900 Stainless Steel Pitcher Pump Foot Valve Housing plus two drain mechanisms strategically located inside the pump body.
For this feature to work properly, the Model 1900 Stainless Steel Pitcher Pump with Drain Back Feature needs to be installed with a Drain Back Water Shut-off Valve and Drain Valve in the incoming water line to the pump. The drain valve is located between the shut-off valve and the pump water inlet. Bison Pumps can provide this combination system.
This feature has components inside the pump body that the standard Model 1900 pump does not have. Therefore, it must be included at the time of purchase. It cannot be added to the pump at a later date.