Heater Problem
10-19-2008, 11:33 AM
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Heater Problem
Hey all, I'm new here. I have a new to me 2000 F150 XL.
I have searched but still haven't conclusively diagnosed my problem. My heater won't heat. Here's what I know.
I flushed the dirty coolant system. Heater hose inlet is hotter than outlet hose.
I can run water through the inlet hose and it does come out the outlet hose. Also, I made sure it flows through the outlet hose when the truck is running. Not a very strong stream but I'm not sure how strong it should be.
Sometimes I do get some heat, just not a lot. Also, when I do occasionally get some heat it is just from the floor. I almost never get heat from the defrost, even though the air blows good up there.
Stopped up heater core?
I also read that it could be the temp blend door.
I can't really hear a difference in the sound when I turn the temp from cold to hot.
Lastly, after flushing the system this morning it seemed to be heating a little better for a few minutes, but after leaving the truck running for a few minutes, I returned to find the air had got cold again.
None of this makes sense to me. Hope someone can help.
Thanks,
Brad
I have searched but still haven't conclusively diagnosed my problem. My heater won't heat. Here's what I know.
I flushed the dirty coolant system. Heater hose inlet is hotter than outlet hose.
I can run water through the inlet hose and it does come out the outlet hose. Also, I made sure it flows through the outlet hose when the truck is running. Not a very strong stream but I'm not sure how strong it should be.
Sometimes I do get some heat, just not a lot. Also, when I do occasionally get some heat it is just from the floor. I almost never get heat from the defrost, even though the air blows good up there.
Stopped up heater core?
I also read that it could be the temp blend door.
I can't really hear a difference in the sound when I turn the temp from cold to hot.
Lastly, after flushing the system this morning it seemed to be heating a little better for a few minutes, but after leaving the truck running for a few minutes, I returned to find the air had got cold again.
None of this makes sense to me. Hope someone can help.
Thanks,
Brad
10-19-2008, 11:49 AM
#2
Senior Member
Welcome to the site!
Suggest you've got a restricted heater core. The flow should be coming out of the core along the lines of a garden hose stream.
Perhaps try to run the water the other way - into the outlet and out the inlet.
If you do opt to replace the heater core - recommend to get the good one. My experience with the bargain-level type has been that about 1/3 of the core is blocked off - have to look really close in between the fins to see this - reducing heat output, and more importantly for me, reducing defroster capacity.
You may have a blend door or airflow diverter door issue. Don't really know of a way to verify this other than opening things up and laying some eyes on it - watching the actuators and doors as you change positions.
Suggest to work first on either getting a good flow through the current core, or replacing it. The temperature difference between inlet and outlet hoses should be barely noticeable if the flow is good and it's not Great White North cold outside.
Suggest you've got a restricted heater core. The flow should be coming out of the core along the lines of a garden hose stream.
Perhaps try to run the water the other way - into the outlet and out the inlet.
If you do opt to replace the heater core - recommend to get the good one. My experience with the bargain-level type has been that about 1/3 of the core is blocked off - have to look really close in between the fins to see this - reducing heat output, and more importantly for me, reducing defroster capacity.
You may have a blend door or airflow diverter door issue. Don't really know of a way to verify this other than opening things up and laying some eyes on it - watching the actuators and doors as you change positions.
Suggest to work first on either getting a good flow through the current core, or replacing it. The temperature difference between inlet and outlet hoses should be barely noticeable if the flow is good and it's not Great White North cold outside.
10-19-2008, 06:50 PM
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Welcome to the site!
Suggest you've got a restricted heater core. The flow should be coming out of the core along the lines of a garden hose stream.
Perhaps try to run the water the other way - into the outlet and out the inlet.
If you do opt to replace the heater core - recommend to get the good one. My experience with the bargain-level type has been that about 1/3 of the core is blocked off - have to look really close in between the fins to see this - reducing heat output, and more importantly for me, reducing defroster capacity.
You may have a blend door or airflow diverter door issue. Don't really know of a way to verify this other than opening things up and laying some eyes on it - watching the actuators and doors as you change positions.
Suggest to work first on either getting a good flow through the current core, or replacing it. The temperature difference between inlet and outlet hoses should be barely noticeable if the flow is good and it's not Great White North cold outside.
Suggest you've got a restricted heater core. The flow should be coming out of the core along the lines of a garden hose stream.
Perhaps try to run the water the other way - into the outlet and out the inlet.
If you do opt to replace the heater core - recommend to get the good one. My experience with the bargain-level type has been that about 1/3 of the core is blocked off - have to look really close in between the fins to see this - reducing heat output, and more importantly for me, reducing defroster capacity.
You may have a blend door or airflow diverter door issue. Don't really know of a way to verify this other than opening things up and laying some eyes on it - watching the actuators and doors as you change positions.
Suggest to work first on either getting a good flow through the current core, or replacing it. The temperature difference between inlet and outlet hoses should be barely noticeable if the flow is good and it's not Great White North cold outside.
Thanks for the reply.
I'm starting to believe more and more that it is a restricted heater core.
Today I blew out the HC with an air hose through the in and out heater hoses. I then funneled in "Zerex Radiator super flush". After sitting for a couple of hours. I flushed it out and replaced with coolant. The heat is still kind of in and out but it is definitely better! The one thing I don't understand is this. Floor is hottest. Panel air is a little cooler and the defrost blows the least heat of them all. Does this make sense? Does the proximity of the heater core somehow affect the heat of these three heat outlets?
Thanks,
Brad