Low coolant, check when engine is cold.
A restricted/plugged heater core can do that. Try flushing the heater core.
if this system uses dex-cool flush the system
hot is hot cool air is cold
Hot air rises. By heating the cool air in the balloon using a propane heater, heats the air and makes the balloon rise
check the antifreeze level in the radiator, when a heater blows cool/cold air there is not enough antifreeze/water in the radiator.
This can happen if the water or coolant level in the radiator is low. There are other causes but this is the most common.
The air doors maybe stuck. Or selector switch is not is not operating correctly.
May have an answer already, but be sure that the radiator is full of coolant.
Check the temperature control cable
Air conditioners are placed at the top as hot air is light it rises up. So air conditioners are placed at the top to help cool the hot air. For example: The hot air which is up becomes cool as you switch on your air conditioner. Then the cold air is heavy so it comes down and then again the hot air goes up and the same process is carried throughout.
replace the heater temperature switch
It could be that you need coolant or it's low.
either your temperature contol switch is faulty or the heater thermostat is faulty you can also check the blend air door switch it might not be switching from heat to cold air http://wiki.answers.com/Q/My_1995_town_car_air_conditioner_is_blowing_hot_air_but_is_full_of_freon_and_the_compressor_is_engaging_any_suggestions
No. Dense air is cool air.
Hot air rises.
just had an rac bloke come check my car which was actually overheting,but also suffering from no hot air coming through the heater when switched to hot. he found it to be the thermostat.
Your probles lies in either the heater switch,to command the selinoid to shut down the valve for the hot coolent,or the selinoid its self.Some where along the line the valve that shuts down in the heater line,to stop the hot coolent from entering the heater core is not closing.May be the shut off valve it's self . As you say..Air is on ,and i still get hot air. so heater switch ,(from hot to cold),selonoid,shut off valve??
Anywhere. Hot air has less density (is "lighter") than cool air.
: If you can turn on the heater but only cold air comes out you should check the blend door. It controls the door to switch from cold air to hot. It sits directly behind the heater/AC controls. It is white square plastic piece (approx 3in x 5in half inch thick and has a plastic screw rod that attaches to the heater/AC controls and they strip out. Hope this helps.
Figure it out.
Because hot air rises and cool air sinks. the reason why is because hot air is less dense than cool air so the cooler air will sink
low on anti freeze or blockage in heater coil
Check that the switch that moves from cool to hot (Is like a sliding switch on a 1990 Corolla I think) is actually opening the vent that controls flow of hot air
I have a 2002 Jeep Grand Cherokee Laredo that was doing the same thing. The problem was a faulty ac/heater switch. You put the switch on ac, compresser engages, lines get cold and frosty, but only hot air is coming out of the vents, because the switch has changed back to heater even though it shows ac. The cure is to have the center panel which contains the ac/heater switch, fan speed switch and temperature control replaced.