Heater core vs radiator
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Is a radiator the same as a heater core? We explain the difference.
As famous (or infamous) as Australia’s scorching hot sun is, we can’t forget the sudden cold snaps and freezing downpours. Never mind winter; these days, even the summer months can be broken up by frigid weather. That’s why there’s never a bad time to check if your car’s cooling systems are in operating condition.
Your car’s heater core is not the same as its radiator, though both are connected and work within the same cooling system. This article will outline key facts about your car’s heater core, including how it’s distinct from the radiator and how to tell when something’s wrong with it.
Natrad is Australia’s trusted cooling and radiator specialist. Whether you suspect there’s an issue with your car or just want your cooling system to get a check-up, we’ve got you covered. Give us a ring, and let’s schedule an inspection.
What is a heater core?
The heater core is responsible for delivering warm air into the cabin and aids demisting the windows so you have good visibility while driving.
How a heater core works.
A car’s heater core is connected to the radiator; in fact, it functions similarly to a small radiator. The heater core is located inside the dashboard and uses hot coolant from the engine’s cooling system to heat the vehicle’s cabin.
Here’s how it works:
- As the engine runs, it generates heat. Your coolant absorbs this heat and circulates through your vehicle’s cooling system, including through the heater core.
- A fan blows air past the heater core, which is hot from all the heated coolant circulating through it. This heats the air.
- This heated air is then pushed into the vehicle’s cabin through the vents, warming the interior of your car.
This diagram visualises how heated coolant circulates between the heater core and the radiator.
If you’d like to learn more about how this system works, you might like to try our interactive cooling system map.
What is the purpose of a radiator?
While the radiator looks and functions similarly to the heater core, its job is totally opposite. Usually situated at the front of an engine bay where ambient airflow is most ample, the radiator is designed to cool your vehicle rather than to heat it.
For the radiator to function, coolant must flow through the engine. As it flows, the coolant absorbs heat generated from the engine, which circulates back to the radiator. As the vehicle moves, cool air hits the radiator and is pushed through the radiator fins, which absorb the engine heat from the radiator. This cools the temperature of the flowing coolant down before it flows back to the engine block to repeat the cycle again, regulating the temperature of your vehicle and keeping the engine from overheating.
Keen to get your cooling system checked? Nip into Natrad for a free cooling system check that’s usually valued at $55!
What are the symptoms of a bad heater core?
The heater core is an essential vehicle component during winter, especially since defogging the windows would be impossible without it. To avoid compromised visibility, make sure to regularly check for signs of failure.
Key signs to look out for:
- Weak or no airflow
- Cold air (not warm) coming through the vents while 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, your cabin filter may be blocked, or that your blower fan is not working properly.
If your car blows cold air when you turn on the heat, it could be because your thermostat isn’t working, your heater core is having issues, or because there is a low coolant level.
A coolant smell or visible coolant leakage inside the car is very concerning and might imply a hole in the heater core. It likely requires replacing, though sealing the leak is sometimes a viable option, too.
Important tip: Coolant leakage inside the cabin can be dangerous for several reasons. Coolant may cause skin irritation. Liquid near or on the pedals can make them slippery and the resulting dampness can encourage mould – not to mention that an unaddressed coolant leak will lead to your vehicle overheating.
If your vehicle is leaking coolant, you must get your cooling system checked at your nearest Natrad or local mechanic as soon as possible. For more information, we have an article available about how to address a coolant leak here
Will a radiator flush unclog the heater core?
A radiator flush can sometimes unclog a heater core, especially if the clog is due to sediment, rust, or other particulates that have accumulated within the cooling system. The flush process involves running a cleaning solution through the engine’s cooling system to break down deposits and then flushing it with water (or a specific flushing fluid) to clean out the system, including the heater core.
The effectiveness of a radiator flush in unclogging the heater core depends on the nature and severity of the clog. Here are a few points to consider:
- Mild clogs: For mild clogs caused by sediment or small particles, a radiator flush might be sufficient to restore proper flow through the heater core.
- Severe clogs: If the heater core is severely clogged, or if the clog is due to a more substantial issue like a physical blockage or internal damage, a flush may not be effective. In such cases, mechanical cleaning or replacement of the heater core might be necessary.
- Regular maintenance: Regular cooling system maintenance, including periodic radiator flushes, can prevent the buildup of debris and particulates that can lead to clogs in the heater core and other parts of the cooling system.
If a radiator flush does not fix the issues with your heater core, it’s a good indication that the problem might be more severe than a simple clog. It’s essential to consult with a professional mechanic to diagnose and properly address the issue to avoid further damage to the vehicle’s heating and cooling systems.
How to flush the radiator and heater core.
We’ve written an extensive guide to explain how to flush your car’s radiator yourself.
Blocked heater core? Come on in.
If you think there’s something wrong with your radiator or heater core, then nip into your nearest Natrad store. Cooling systems have always been our specialty.
Stop by, and we’ll examine your cooling system for free!
