car radiator
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What’s the difference?

Have you been experiencing trouble with your air conditioning system lately? With the cooler months on the way, now is the optimal time to give the system a once-over to pinpoint any potential problems. We don’t want you to get stuck with no heating when you least expect it!

That’s why we’re going to be covering key facets about your heater, which is responsible for heating and defogging the cabin of your car. A heater core is quite visually similar to a radiator, which can sometimes lead to mix ups. They are both heat exchangers and comprise fins and tubes to dispel heat. To clear things up, we’ve created a simple guide on how your heater core works within the A/C system.

Natrad offers free cooling system checks valued at $55! Speak to the cooling specialists today to keep your A/C in top shape.

Heater core vs radiator

A heater core is like a tiny radiator. It consists of an inlet and outlet, a core with fins and tubes as well as side or header tanks. The shape and size varies from car to car, but it’s overall function is pretty standard. Some systems use a specific valve that regulates coolant flow into the heater core, where others simply have it circulating through constantly and flaps are opened when heating is desired in the cabin. The heater core is responsible for delivering warm air into the cabin and demisting the windows so you have good visibility while driving.

Main function

So how does it work? While the heater core is actually a part of your air conditioning system, it is directly tied to the wider cooling system. This is because of the hot coolant flowing through it, where all other parts of the air conditioning system utilise refrigerant. As the heater core is required to produce heat, using hot engine coolant is the ideal of way of achieving this.

See diagram here (depicts flow of coolant through heater core) IMAGE CREDIT: Quic Transmission & Automotive Services

cooling system diagram

As you can see above, the coolant flows through the system until it eventually reaches the heater core. Coolant enters via the inlet and passes through the heater core’s tubes. The heat from the coolant warms the air passing through it, which is pushed through the core’s fins by the blower motor. This air is then directed into the cabin via the air conditioning vents.

Important tip: a good way to maintain the air conditioning system is to keep it running for at least 5 minutes every drive. This helps keep the system lubricated and helps prevent clogging or build up of bacteria.

What does a radiator do?

While the radiator looks and functions similarly to the heater core, it’s job is completely different. Usually situated at the front of an engine bay where ambient airflow is most ample, it is designed to cool rather than heat. Ambient air from the moving vehicle passes through the radiator fins, while hot engine coolant circulates through its tubes. The airflow helps cool down the coolant as it flows back to the engine block, thereby keeping the engine from overheating.

How do they work together?

While they have 2 separate roles within the car, they are inherently connected thanks to the cooling system and its coolant. By using the natural heat from the hot coolant, the heater core efficiently disseminates warmth to the cabin of the car while still protecting the engine. The radiator aides this process by removing heat from the coolant before it circles back to the engine, and then it all starts again.

Failure symptoms

The heater core is an essential component during the winter months, especially as without it, defogging the windows would be impossible. To avoid compromised visibility, make sure you regularly check for signs of failure.

Key signs to look out for:

  • Weak or no airflow
  • Cold air (not warm) coming through the vents when the heater is on
  • Coolant leakage visible inside the cabin or a damp smell

What do these signs mean? A noticeable difference in airflow could indicate that the heater core fins have been clogged and are restricting airflow. A coolant smell or visible coolant leakage inside the car is a bit more sinister. This is likely due to a hole in the core somewhere and the coolant is escaping into the cabin. This is typically where heater cores are situated. It may need to be replaced in order to get the system working although sometimes sealing the leak is possible.

Important tip: coolant leakage inside the cabin can be dangerous for several reasons. Liquid near or on the pedals can make them slippery, and the liquid itself can encourage mould or rust which can then corrode the floor of your car.

If the cause of the problem is a leak, your car may be losing coolant slowly. If you notice a low coolant level but can’t locate the source of the leak, it could be escaping into the cabin of the car. Coolant loss will cause engine overheating which is not good for many parts inside the system!

What now?

If you’ve noticed any of the above symptoms, then it’s time to take action. Talk to a knowledgeable technician at your local Natrad store to properly diagnose the problem. The fault may be obvious or some deeper digging might be needed, but whatever repair is required, Natrad can help.

Natrad technicians are the specialists in cooling system and air conditioning repairs. If you need advice on your heater core, get in touch with your nearest store today.