The heater fan ONLY blows the air, it does not make the temperature of that air. Your heater temperature controls how hot the air is. Adjust your heater temperature for hotter or cooler air.
the heater blows warm air when fan is on low but blows cold air when fan is turn to higher setting
The heater is like a small radiator(heater core) usually located in the dash. The fan blows air through it and heats the car. There are two heater hoses that carry coolant to & from the heater core.
most likely your heater-core went bad. if you car runs perfectly fine besides having heat. if you car gets up to normal temperatures, doesn't over heat. the fan blows, but just blows cold air. then it is the heater core.
Only blows cold air with the a/c on while driving, your cooling fan or fan clutch is bad depending on the year, make and model.......... Only blows cold air with the heater on while driving, you will have a bad or broken internal a/c - heater control door.....
it could be your fan motor is going to go
Some problem with the fan or related components most likely. the heater core has no moving parts and the fan just blows air through it.
The heater in your car uses waste heat generated by the engine. The hot coolant from the engine flows through the heater core causing it yo get hot. A fan then blows air over the hot heater core into the vehicle.
This can happen if the water or coolant level in the radiator is low. There are other causes but this is the most common.
See "Related Questions" below for a complete discussion on possible causes and more importantly: fixes
There are different types of heating coils. Most are electric heat strips, refrigerant coils or hot water(hydronic). Your furnace\heater fan blows across the coils to heat your home or office.
because the heater uses hot coolant/antifreeze to heat your car....the coolant passes thru the heater core, then a fan blows the warm air thru your vents Your heater core is leaking and must be removed and repaired or replaced.
One.