Could be,
low on coolant,
stuck open thermostat,
plugged up heater core,
faulty temp blend door actuator,
No, not if it's on a heat setting. Most home thermostats have a "Fan" setting that will blow cold air if the attic is cold.
The heater does not blow air because it emits infrared rays that have heat molecules within them, thus releasing heat, not blowing it. A heater does not blow air becasue there is no moving air source within the heater. The heater emits infrered rays that cause heat to slowly flow out of the heater.
More than likely you will not have heat being the water wont be circulating through the heater core , When the hot water passes through the heater coil the air passing through the heater coil makes heat blow out the vents when you have selected a heat setting on your controls.
it wont blow heat itll blow cold air
you need to replace your heater core
heat core. leak. thermostat. no antifreeze.
check heater core could be cloggedCheck the engine coolant level also.*no, the heater relies on the engine for heat and when you drive the engine warms generating heat:)*
The heat valve is stuck open.
Heater core may be defective
The flap is stuck open that controls when and where the heat goes
When a car runs, it produces heat as a wasted product. This heat is then used to heat up air and blow it at you. This heat will be created even when the heater is off, so using the heater should not lower gas mileage.
The heater bypass valve is not fully closing, or leaking hot coolant into the heat exchanger.