Heater Control Valve Requirement

jonn6464 said

The A/C is a separate under dash unit, self contained. The heater core is in a different box, with it's own outlet ducts.

I was thinking there would be some radiant heat just from the hot coolant passing through, but I wasn't sure how much that will be felt.

I saw a little electric valve for $30 and thought maybe I could wire that into the heater fan switch. Switch ON=Valve Open
Switch OFF=Valve Closed

Click to expand...

Yes there will still be radiant heat in the car from hot coolant going through the heater core if you don’t have a valve.

I know I definitely notice the heat in the car on longer drives if I forget to close the temp control slider on the dash that closes the heater valve. I don’t have AC in my car, but it’s really obvious if I forget to reset the temp slider in the spring and the fall. I need the heat in the cool/cold mornings but in the hot afternoons leaving the slider on warm heats the cabin up fast even without the blower going.