What to Do If Your Car's Heater Is Blowing Cold Air

If you've been sitting in your car for some time on a cold, frosty morning and still cannot feel your toes, you've got an issue with your heater. This can be very unpleasant, and you will certainly want to get to the bottom of it, no matter that Australian winters are on the short side. What could be going wrong, and what should you do to heat everything up?

Heating System in Action

Your car's heating system is relatively straightforward and will rely on the heat generated by the engine to cool the passenger compartment. Everything starts with a front-mounted radiator that is attached to the engine and circulates coolant in order to regulate the motor. If you want to use some of that heat within the passenger compartment, you simply need to activate a dashboard switch that will divert some of the untreated hot water through a separate radiator.

This radiator core is situated just under the dashboard, and the heated liquid will flow this way once it has been diverted. You will then turn on a rear-mounted fan that will pass across the core of the heater and blow the warmth towards your toes.

Cold Air

If the fan is working but you are only getting cold air, this could be down to one of several reasons.

• The heater core could be blocked, which can happen over time due to a buildup of contamination or internal corrosion.
• The coolant level may be low, which is an even more pressing problem, as it could also cause the engine to overheat.
• Or, you may find that a mechanism known as the 'blend door' is faulty and is not diverting the air in the correct direction.

Where to Look

You can check the coolant level right away by lifting up the bonnet and looking at the coolant pot. If this seems to be okay, then have a look around the bulkhead to see if you can see where the fluid pipes hook up with the heater core. If you're careful, you can check the temperature of these hoses or use an infrared thermometer to be perfectly safe. If these hoses are hot but you're still not getting anything inside, then the heater core will need to be serviced.

Taking Action

For the time being, you may have to suffer in silence, but you should book the vehicle in for an auto heating repair service at the same time. Your mechanic will be able to diagnose the problem so that any subsequent journey to work will be a lot more pleasant.