Signs of a Bad Heater Control Valve

A heater control valve is a component in a vehicle's cooling and heating system that controls the flow of hot coolant to the heater core, allowing warm air to be blown into the cabin. When this valve starts to fail or becomes faulty, several symptoms can arise. Here are some common signs of a bad or failing heater control valve.

Source: https://www.truckac.com/produc....t/heater-parts-heate