Plumbing in Fargo is a heating-season trade with a basement address. Supply lines in exterior walls, sill cocks, and the run to a garage freeze while the thermostat upstairs looks content. When they thaw, they flood the same basement that holds the furnace. Shut the main if you cannot isolate the break. Know where that valve is before you need it. If the meter moves with the fixtures off, the leak is still live.
Sort the water. A frozen condensate line stops the furnace. A frozen supply line soaks the house when it lets go. A sewer vent full of frost makes drains gurgle and smells that a cable will not cure. Ice-dam water from the roof is not a pipe. Say which one you see. Spring melt on valley clay then tests the sump and the window wells, which is the end of the heating season, not a separate climate. A pump that sat all winter deserves a test before that melt arrives.
Older central houses may have galvanized supply and cast iron that fail on age in the middle of a cold week. Newer south-side houses hide PEX and manifolds in finished basements, so a leak travels. Water heaters work all season and weep at the base when you are distracted by the burner. Name gas or electric, the vent, the pan, and the shutoff. A limping tank in a house that is about to get a new shower valve should be said out loud.
Hose bibs on the windward wall freeze first because the fetch is long and the wall is cold. Shut them from inside and drain them while you still control the calendar. Do not send a sump into a sanitary drain it was never meant to feed. Discharge it away from the foundation or the thaw brings it back through the well. Floor drains in mechanical rooms are the last line. Know whether they are clear before the freeze-up thaws at two in the morning.
Say leak, freeze, drain, or water heater, and the neighborhood. Say if the heat is on and if you can shut the water off. If the stain is under an eave, say ice dam so the roof is not ignored. Call the number on this page.