2000 f150 5.4 still no heat
 

Hey there guys first time post here but long time user of the forum. I'm having the same issue as many others with the heat blowing cold air. I have read through the other post ad tried the blend door, actutator, vaccine lines, control nob, and both lines going in and out are hot to touch when warmed up. I am now lost!! Any help would be greatly appreciated.

what exactly did you do with the blend door? i had the same problem. what i did was with the heat turned on, i slapped the side of the blend door and it opened up. hopefully your door just may be sticking like mine was.

I actually cut through the glove box to access the door and it is still fully functional.

Could it possibly be the thermostat stuck open? I have read that if it is stuck open you won't get heat. But both hoses through the firewall get hot.. Any ideas??

If both hoses are hot the problem is on the other side of the firewall, not in the engine compartment.

That means the airflow is not going through the heater core for whatever reason. It might be the blend door, it might be a vermin nest or a plastic bag. You'll have to go in there and look again.

Alright ill have to check again after work. Where should i look for obstructions? just clear the blend door? Thanks for the info! Hopefully I can get this fixed before we get any colder down here. If the weather stays around 70 all winter I just might not need heat this year lol..

Well still no luck figuring this out... Nothing seems to be blocked anywhere.

Gonna attempt to flush the heater core today. Hopefully this fixes the issue.

If both hoses are hot, near the same temp, while the blower is running, there's nothing wrong with the heater core. If the heater core were blocked, you'd have one hot and one cold-to-warm hose, depending on the amount of restriction. This is a simple hydronic heating system. Circulate hot fluid through a radiator, blow air across the radiator, extract heat from the radiator into the air. Simple.

Before embarking on what might otherwise be yet another wild goose chase, you might want to go back and double check your previous observations. If they were inaccurate, then any diagnosis based on faulty observations will also be faulty.

just courious, as yours blend door is buried behind your glove box and you said its funtional. on my e-350 i can put my ear up close to the blend door in the cab, i dont know how close you can get to yours with your ear. BUT when i get close to mine and just turn the AIR on in the cab, i can hear a difference in sound as soon as i turn the control nob over too the heat seating.

i am just thorwing out a sugestion to see if you can hear a difference like i can. that will give you a idea if the blend door is moving or not.

Howdy, I am new to the form and I am having the same problem, No Heat and the fan only works on high. I just got the truck, 235000 on it. there are a few other thing I will be fixing also, but it was 9 out this morning, so lets start with Heat... Thanks:-hijacked