Most likely a replacement heater core
Need to check the fan.
Car heaters need a few moments to warm up.
might need to replace blower motor
Convective heat transfer is used when a fan is blowing, as the movement of air helps to carry heat away from a surface, allowing for more efficient cooling. The fan accelerates the natural convection process by increasing the airflow over a surface, enhancing heat transfer.
You may need to have your AC charged
you need a new thermostat and possibly some anitfreeze
It probably has a small leak somewhere. You need to take it somewhere and let someone check it and probably need a charge of R134.
Has the fan stopped blowing or is the air coming out cold? Need more info please, make model, year and such.
you probably need a new blower motorCheck the fuses too -See "Related Questions" below for more
All fires need three things to burn: fuel, heat and oxygen. When you fan a small fire, you are getting more oxygen to where the fuel and heat are.
It is broken. AC's usually blow cold air.
if the air is blowing but it is not hot then it is your heat coil and it might have went bad and you might need to get a new one. a heat coil is a coil located around your engine area, and as it is heated air blows through it into your car.