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Heater does not heat up

6K views 16 replies 11 participants last post by  xraye39 
#1 ·
Hello I have a 525i 2003 and the heat doesnt heat up until you run the temp up to about 80when I put it on 70 the air is warm but not hot....most of the time the air feel luke warm! has anyone else had this problem and what did you do to fix it....The radiator has been replaced and all hoses are good.
Thanks
 
#4 ·
If you are not suffering from cooling system problems (clogged system limiting delivery of coolant to the heater core) then I would look to a faulty FSU (blower resistor); do a search on this forum for FSU and you might find what you are looking for.
 
#6 ·
I too found that you have to crank the temp way past 70 and then it works pretty well.

I also noticed that I have heat in a short distance and short time period. Its warm air before the engine temp gage is 25% up assuming 50% is the straight up, fully warm position.

Wish I had seat heaters.
 
#11 ·
guntersr,

Has it always been this way, or just since the cooling system work. OR, since the very cold weather you've been having?

It could be perception, or air in the system, due to a les-than correct system bleed. OR, it may be a failing heater valve. Is the heat the same on both sides, or different? If different, the valve may be bad.
 
#13 ·
Could be low coolant or a locked-open thermostat. Mine has given the open-thermostat symptom a few times...and then it goes away. (Yes, cooling system overhaul is planned, but money and the problem of no garage space get in the way).

As for seat heaters, in both my car and my grandfather's car, I find that the temperature comes up before the seats get warm. They're really nice, but the car's pumping hot air as the seats warm up.

When you put it on the defrost setting, does the air get hot? The computer that controls the heating is highly variable, and tries to make itself as unobtrusive as possible, so it seldom blows noticeably hot air, unless you ask it to.
 
#14 ·
it happened to me twice:

the first time it was due ro low coolant in the car.. found a leak and made an overhaul for the engine coolant system. or you can add coolant every once and a while! :D

the second time it happened i changed something like a thermostat for the heater it self...

dont know whats the name of that part exactly, but its the part the opens and closes when u switch on the heater. its a heater thermostat i guess! :dunno:
 
#17 ·
The radiator has been replaced and all hoses are good.
Thanks
Who refilled and bled the cooling system? Ya might have an air pocket in the heater core or your thermostat could have failed and be in the stuck open mode.
 
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