Does a car need the heater hose to run?

A car does not necessarily need its heater hose to run because the purpose of the heater hose is not to transport essential fluids for combustion or cooling; instead, it carries hot coolant from the engine's cooling system into the vehicle's heating core, warming the car while the engine is running. Without a properly connected heater hose, the cabin can get uncomfortable due to the lack of hot air during cold weather, but most importantly, the car can still operate without issues.