Could it really be this easy?

Not sure what is in your wet bay but I would make sure the city water connection has antifreeze in it. To do this, make sure the pump is off. Open a tap in the bathroom, then push in the little button in the middle of the city water hook up connection. The reason you do not want the pump on, is because if there is a lot of pressure in the line, when you push the button in, the antifreeze will displace an o ring in the connection. (Ask me how I know) If there is only a little or no pressure, the o ring will remain in place.

Also make sure you have anti freeze in your exterior shower/water hose.