air door not moving or air pocket in system..check that both hoses to heater core are hot, if not u have a problem with flow such as previous suggested or bad water pump or thermostat. if both are hot the n problem lies within the heater controls.
can you please clarify what you mean, do you mean that the front heater blows cold but the rear blows hot or do you mean that when the heating is on cold it blows hot? many thanks paul
it could be the heater core and ac housing unit that allows hot air to be mixed with the cold air or it could just cancel out the cold due to the motion of the car
The thermostat may be stuck open.
Get the air out of your heater core.
heater hoses might have been disconected
ihave a 1986 chevette that when i turn defrost on it blows out heat and when i put heater on it blows out only cold air? ihave a 1986 chevette that when i turn defrost on it blows out heat and when i put heater on it blows out only cold air?
The most common reason a automobile heater blows cold air is the water level is low. Check the water level and fill to the appropriate level.
the heater blows warm air when fan is on low but blows cold air when fan is turn to higher setting
you must have low coolant or a bad heater core
I would say that your heater core is ok...it sounds like you have a bled door promlem in the dash.
we changed radaitor & thermastate , now heater blows cold air
It is because your heater is having to heat up so its blowing cold air out while its heating up.This means your heater is not very efficient and it needs to be checked.