The answer to 'supply line frozen' is that a frozen supply line is a common plumbing issue that occurs when the water in the supply line freezes, usually due to cold temperatures. This can happen to both hot and cold water supply lines and can lead to a loss of water pressure or even a complete loss of water flow.
Some common causes of frozen supply lines include inadequate insulation, drafty areas around the pipes, and sudden drops in temperature. Symptoms may include no water flow, reduced water pressure, or water leaks around the frozen section of the pipe. Solutions can include insulating the pipes, using a space heater or heat tape to thaw the frozen section, or in severe cases, calling a professional plumber to replace the damaged pipe.