What is a heater controller valve? What are the symptoms of a heater controller valve failure? How can you detect a heater control valve malfunction?
What is a Heating Controller Valve?
The heater control valve can be found in almost all vehicles as a cooling or HVAC system component. The heater control valve controls the flow rate of coolant from the engine to heater core. It attaches to the heater core inlet pipe hose and is located near the vehicle’s firewall. The heater core is blown hot air from the vehicle’s grilles by the hot coolant that is pumped from the engine when the valve is open.
Manual systems use a jumper cable or engine vacuum to control the valve. In wire systems, the control cable is connected to a heater button on the console. The engine vacuum is used in vacuum controlled systems to move the valve.
A control module manages the valve on vehicles equipped with automatic temperature control systems. The control module can adjust the temperature to suit the driver’s preferences. Electronic control of the timing of valve opening/closing is provided by an electronic vacuum system or an electrically-assist solenoid.
Heating Control Valve Failure Symptoms
A bad heater control valve could cause issues with the vehicle’s cooling system or heater operation. A faulty valve can cause the following symptoms:
Heater not blowing hot air
A heater that does not blow hot air is the most obvious sign of a defective heater control valve. The heater core’s coolant flow may be blocked or stopped completely if the control valve becomes jammed. Without a liquid flow to heater core, it is impossible for heaters to blow hot air.
Coolant Leaks
Coolant leaks are another common problem with heater control valves. Coolant can leak from the control valve if it cracks or wears over time. The coolant constantly comes in contact with control valve. It can corrode, wear and become brittle, which could lead to leaks. In this case, it is necessary to replace the control valve.
Inconsistency with Heater Blowing
The heater may malfunction if the control valve is not able to control the flow of coolant. Sometimes the heater will blow hot air and sometimes turn to cold air. You can also see the temperature gauge fluctuate quickly.
