Its been right about freezing here in San Antonio and im getting tired of having no heater! Im pretty sure it was a stop a leak substance that i put in my truck that started this problem. One heater hose is really hot and one isnt, so it has to be my heater core.

My question is, is there a way to flush it out and be okay on my own? Or is it safer to just have it professionally done? Pics and directions would be great!
Its a 92 f150 with a 5.0, by the way.

Thanks in advance

 

Not likely. If the heater core was blocked, no coolant would flow, and neither hose would get hot. Yours has the symptoms of an inoperative temperature blend door. Read these:

. . . . Even if the heater core was blocked, it's never worth repairing. They're cheap, and super-easy to change; easier than changing the headlight bulbs. At most, you'd reverse the hoses at the heater core a few weeks before flushing the coolant.

 

thanks so much for that info. So where do you think i should start off? maybe replacing the blend door lever? im not sure at all what to do to see if it helps

 

You don't start by replacing parts - you start by inspecting/testing. Fold the glovebox down & take a look. See what happens when you turn the ****.

 

Okay what should happen when going from cold to hot and vice versa?

 

I tuen it all the easy left for ac and the wire goes all the way to the left. Then when I turn it all the way to heat it goes all the way to the right. Suggestions?

 

since it's free i would pull the two heater hoses off the core at the firewall stick a garden hose on there and flush the heater core out flush it in both directions. reinstall the hoses and see what happens. this may not solve the problem but will eliminate one possible cause and only cost you a little time. if your heat works better then i would replace the heater core as it will plug up again.

 

Finally got around to having time to fix this. It was a really bad clogged heater core. Flushed out the whole system 3 times. Still wasnt doing much so I just did the heater core and oh man was it dirty. Now it heats like its straight from the factory. Thanks for all ya'lls help