I have a GSHP running in open loop using water from my well. The water discharges through a buried pipe that comes to the surface on a stream bank. When it gets very cold at nite and the HP does not run for many hours due to programmed setback, the water outlet sometimes freezes up. It is insulated and covered where it comes to the surface, but that is obviously not good enough. Is there a preferred way to make the surface breakout in cold climates?