How does the heater control valve work?

[Explorer_PL]

The heat in my 06 is weak or not as hot as in our 07, so I can compare directly between the 2. I am watching the heater control valve but I do not see the lever moving ever. When I took the vacuum hose off it, I did not feel any suction.
How do you test it ? .
I replaced it about a year ago with a Dorman unit so who knows.
When is it supposed to close and open ?

Thanks

M

 

[07EddyB]

I replaced mine a few months ago due to a leak. I never really traced things down but I did learn this. The default is open. In other words, vacuum closes the valve - it doesn't open it. You should never have low heat due to no vacuum. It's possible that the diaphragm got bunched up underneath so it can't open all the way but even then the valve would be almost completely open. I know this because i spent considerable time playing with the old valve.

Yeah - I need a life.

 

[BrooklynBay]

Try to move it manually. Feel the hoses before & after the valve to determine if the temperature is the same.

 

[Explorer_PL]

EddyB-

You have a life, it's called keeping the Explorer alive
It's most of us main job here LOL

But my question is when and if I should feel vacuum at the grey hose ?

 

[07EddyB]

I would imagine that you should get vacuum when you either move the temp selector to cold or you turn on the air conditioner. I'll look at mine this weekend and see what it takes.