Heater Control Valves

The heater control valve (or hot water valve) toggles open and closed to regulate or prevent hot engine coolant from flowing through the heater core. The heater core is a major constituent part of the heating system. It uses this heated coolant to warm the air supplied to the cabin. There are multiple varieties of valves that all basically supply the same function in different ways, but all of them are what keeps out the chill when the temperature plunges.

A cable operated heater control valve utilizes a Bowden cable to drive a flap inside the valve. As you move the lever on your HVAC control, the cable moves the flap. A vacuum valve does this with a pintle and diaphragm, except this type is typically open. This way heat may still be provided even when it is defective. Vacuum is supplied by the engine through a switch in the dash. Electronic controls are pulse width modulated or controlled by a simple on/off solenoid. PWM offers more control over the coolant flow. The number of pulses sent from the computer prompts the position of the solenoid.

Heater control valves are regularly replaced because they leak; but if the heater hoses are being replaced, why not just swap out the valve as well? Take care of it now and prevent more work down the road. If the valve is stuck closed, denying the heater core of hot coolant, the inlet hose to the heater core will be hot and the outlet hose much cooler. Some other symptoms of fatigue or failure of the valve would include leaking coolant or the heat of the air not altering as you adjust the temperature. When replacing the valve remember to inspect all heater hoses and replace them if needed.

All of our heater control valves are a high quality and a direct fit OEM replacement. Rest assured before it ships we substantiate it is for your specific application. We offer this free service to our customers to guarantee their peace of mind. To utilize this service, simply enter the application Year, Make, and Model during checkout, and our system will verify the fitment before the item is shipped. Our valves have superior service life, resist abrasion and corrosion, and maximize performance. If the valve is being replaced due to corrosion, flush the coolant to prevent additional problems!