With high energy costs even for minimal winter heating, most people with summer homes in Northern states do a complete winterizing process come fall. This prevents burst water pipes, both pressurized and non-pressurized. One of the key steps in the process is shutting down a well water pump and draining out all of the water in pipe located above the freeze line.
Most deep well systems subject to sub-freezing conditions during winter have the tubing run between the house and the well buried at least five feet under ground, which is below the freeze line in the majority of locations. On the outside of the well casing, the tube to the house is connected to a brass pitless adapter which protrudes inside the well casing pipe. On the inside of the casing, a vertical slide fitting connected with the drop pipe and submersible pump exactly slides into a sloped recess in its mating side fitting in the well casing. An O-ring held in a recess in the slide fitting is pressed tightly between the two parts of the sliding fitting, and a pressure-tight seal is established. Unless the owner has another valve in the pipeline outside the well casing that is at least lower than the freeze line, there is no way to drain water out of the pipe line between the pitless adapter and the line coming up into the house under the floor. Any section of this pipe that is above the freeze line would be subject to freezing and bursting the pipe due to the 10 percent freezing expansion phenomenon.
Extra Valve Method
One solution is to install an extra T and a short length of tubing up to the surface on the pipe to the house near the well casing. A tight shut off hand valve can be installed on this vertical riser pipe with a U-return or threaded cap on top to keep out dirt. When fall comes, the owner simply shuts down the pump at its electrical breaker, opens a drain hose on the pressure tank, and drains the household system by turning on all the faucets, draining the hot water tank, and flushing all the toilets several times. When everything is drained, any water in the lines under the house can be ejected at the added outside valve by pushing it out with compressed air from an added drain valve between the well and the inside check valve.
Pitless Adapter Method
If the pitless adapter is kept clean, especially the 1-inch NPT blind fitting at the top of it, the owner can screw in a homemade T handle tool, lift the adapter out of its slide about a quarter inch or so (not completely) just to break the seal and let the water drain back out into the well. For this purpose, a vent valve should be installed in the pipeline between the check valve in the house and the well, to let air into the system to replace the water being drained through the pitless adapter.
Finishing the Shutdown
Close all the household water faucets and the water heater valves as well as the extra drain valves, and relax knowing the well system will weather the winter. DO NOT turn the pump back on until spring.