Q: Car heater blowing cold air.

There are a few different reasons why your heater could be blowing cold air. First, there may be a problem with your Heater controls. Inside your dashboard there are a series of doors that direct airflow. If one of these doors isn’t operating correctly it is possible that only cold air will come out of the vents. The next possibility is that your heater core is blocked or restricted. The heater core is pretty much a small radiator inside your dash that the fan blows air through to get hot air for the interior of your car. Sediment can build up in your cooling system over and clog the small passages inside your heater core. When this happens the coolant can’t flow through the heater core and warm the air in the cabin. Sometimes the heater core can be flushed out, but it is also possible that it may need to be replaced if the blockages cannot be removed. The last possibility is that your engine is low on coolant. If coolant has leaked out and there is now air in your cooling system the air cannot transmit heat into the heater core. I would recommend you ask for help from a mechanic to check your car for these concerns so your heater can get back to normal function.