Climate Control
Heater Valve
A heater valve opens and closes coolant flow to the heater core so you can control cabin heat. We carry 32 heater valves from $12 to $163 for vehicles from 1974-2018, from Four Seasons, Motorcraft, GPD and UAC, with fits for the Ford Explorer and F150 and the Chevrolet Malibu.
Shop heater valve by vehicle
How a heater valve works
Not every vehicle has one, but on those that do, the valve sits in a heater hose and controls how much hot coolant reaches the heater core. Valves may be worked by a cable, by engine vacuum, or by an electric actuator controlled by the climate system.
When the valve closes, the core cools down and the air conditioning can work without fighting heat from the core.
Signs of a bad valve
A valve stuck closed gives no heat. A valve stuck open sends heat even when you select cold, which can make the air conditioning feel weak. Plastic valves can crack and leak coolant.
Check the cable, vacuum line or electrical connector before replacing the valve, since a broken control can mimic a failed valve. A leaking valve will often leave dried coolant crust around its body.
Choosing the right valve
Match the control type, hose sizes and year from the fitment table. Valves in this category are made of plastic or steel. Check the flow direction marking and install the valve the same way as the old one.
Let the engine cool before opening the system. Clamp off the heater hoses if you can to limit spills, then refill and bleed the cooling system after the job.
Heater Valve questions
Does every car have a heater control valve?
No. Many vehicles let coolant flow through the heater core all the time and use a blend door to control heat. Check whether your vehicle lists a heater valve.
Can a bad heater valve make the AC blow warm?
Yes. A valve stuck open keeps hot coolant in the heater core, which can warm the air even with the AC on. Check the valve's control cable, vacuum line or connector first.
Which way does a heater valve go in?
Most valves have an arrow showing coolant flow. Install it the same way as the old valve and match the hose routing. Replace worn hose clamps while the hoses are off.