No heat - help!!!

I have a 97 ford taurus 3.0 130,000 miles and no heat I've had heating core replaced, system and core flushed and back flushed and thermostat replaced but I only have heat when going above 3000 rpms and it is warm not hot. Only other things can think of would be water pump but car isn't overheating, electronic blend door actuator or the steel lines between the engine and heating core are clogged though doesn't sound likely.. I'm researching like crazy to get this fixed so i can drive my kids around wout freezing or worrying about vision impairment because i cant defrost my car but im a single mom who knows nothing about cars and im running out of money... please help me figure this out?

acculator could be gumed up or blend doors arn't opening like they should? another thing you said you had rad boiled and cleaned out or did you do it with the t that is in if installed heater hose and just used water to do this flushing? i doubt water pump if it's not leaking fluid or making a hell of a noise it's possable on water pump but i don't really think so. have you tryed bleeding the air out? another thing when car is cool take rad cap off and see if it's curculatig?

it was flushed with garden hose multiple times n taken in for free diagnostic and told heating core needed replaced i had that replaced there was heat for a day or two then back to cold i had it reflushed and backflushed with garden hose and had the thermostat replaced but still no heat unless over 3000 rpms... Thank you any other thoughts or ideas would be greatly appreciated :)

Does you car take too long a time to reach normal operating temperature? Once your car reaches normal operation temperature, does it stay there after warming up? Normal operation temperature is the halfway point on you temp gauge (about 200 degrees)

No it gets to warm temp normally and stays there

As mentioned above, checking for air in the system may be the place to start, especially with all the recent activity with your car's cooling system. There might be an air pocket that is keeping the heater core from working effectively. Often though trapped air will cause the temperature gauge to fluctuate randomly.

-Rod

it was flushed with garden hose multiple times n taken in for free diagnostic and told heating core needed replaced i had that replaced there was heat for a day or two then back to cold i had it reflushed and backflushed with garden hose and had the thermostat replaced but still no heat unless over 3000 rpms... Thank you any other thoughts or ideas would be greatly appreciated :)

that's why i wanted you to let car cool and take rad cap off and see if it's cirulating?

The temperature gage doesn't fluctuate and it has been flushed and back flushed several times and ive drove it around in low gear to get rid of air pockets that might have occured. is a garden hose not sufficient to flush it?

Ive taken cap off when cool and looked at level of antifreeze but how do i know if it's circulating? Sorry everything i know i've just recently learned and its still not much...

no that's not near as good as taking it to a rad shop and they boil it out and even paints it like a new radiator. but really i would look to see if rad i is circulaiting?

you have to start the car to see if it's circulating but make sure it's cool enough before trying this you could get burnt if not cooled down.

Thank you! i will check that

I'd take it back to who ever replaced your heater core. They should back up their work. For a temporary fix you might try covering half the front of your radiator with a piece of cardboard to give you a little more heat. Only do that if its really cold outside.

by the way is the fan for heat blowing out vents strong?

My uncle kinda replaced it for me not a shop when i was visiting out of state so can't really do that but the cardboard is an interesting idea.. thanks! Oh n antifreeze is circulating.. can someone maybe tell me how to check the blend door for problems?

Not strong no but it does blow out ive shut all but the middle vents to direct flow better

on most cars you take glove box out and you should be able to see blend door open when you move to heat and close when you turn heat off.

Be careful the cardboard does not come in contact with any fan that might be in front of the radiator. Also, run your heater fan on low not full blast. This will give hotter air though not as forceful. If you notice truckers this time of year have their radiators blocked with a button tarp on the front of their trucks to get more heat.