Little or no heat, have flushed system, replaced thermostat.

Thanks I will llisten to see if i can hear operating.

I will look and verify vacuum line hasn't been disconnected. What is best way to insure that it is working properly?

Toward the bottom of the valve is a lever you can see if it changes when switch temp. control. If it doesn't move it can be moved by hand manually to see if heat works then. A helper is handy!

do you hear any clicking under the dash? you never said.when you change the controller from hot to cold do you hear any movement under the dash? is there any temp change at all?