Heat not working on 2004 Ford Mustang

Took car to mechanic,said needed new thermastat and a good flushing.He did that,heat still not working.He said heater core was fine,which is what I thought it was.But mech. said good water flow thru core.Taking back in morning,any advice????

Asked by for the 2004 Ford Mustang
3 answers 4 comments
thermostat stuck open
Thank you for reply,please read my reply from anwser #1
Blend door or blend door actuator. .........Sorry about the wallet flushing thing.
Thank you for your time,heater is still only working sometime.Going to dealer tommorrow,going to get price on actuater and blend doors.Thanks again
Your welcome , hope that fixes it.
ck to see what temp is of coolant may be stuck open thermostst
Just got back from garage,thermostat was fine(atleast when I got there),computer said temp good 218.Mechanic did bleed system (I believe from nut where hose comes out of engine then to heater core).Didn't seem to work at that time.But on way home, after running car down 295 pretty fast,heater now working.Letting car cool down now,crossing fingers,going to try it again.Thank You