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How Do You Unclog A Heater Core

If you have an older car, you may be wondering how do you unclog a heater core. The answer is actually quite simple and does not require any special tools or skills. Here are the basic steps: 1. Open the hood and locate the radiator. 2. Locate the small diameter hose leading to the heater core. 3. Place a funnel in the neck of the bottle and pour in the distilled water. 4. Add the vinegar to the bottle and screw on the top tightly. 5. Shake the bottle vigorously for about 30 seconds. 6. Remove the funnel and pour the contents of the bottle into the radiator. 7. Fill the radiator with water and start the engine.

What is a heater core?

When a car’s heater core becomes clogged, it can cause the engine to overheat. The heater core is a small radiator-like device that is located under the dashboard on the passenger side of the vehicle. It is connected to the engine’s coolant system and circulates hot coolant through small pipes to heat up the cabin.

If your car’s heater core is clogged, you will likely notice that the cabin is not getting as warm as it should be. In some cases, you may also see steam or coolant leaking from under the dash. If you suspect your heater core is clogged, it’s best to take it to a mechanic for diagnosis and repair.

What causes a heater core to clog?

There are a few things that can cause a heater core to clog. The most common is simply dirt and debris buildup over time. This can happen even if you regularly clean your car; it’s just something that happens naturally as your car ages. Another possible cause of clogging is rust. If your car is older, or if you live in an area with a lot of road salt, rust can build up in the heater core and cause clogging. Finally, if there is a coolant leak somewhere in your car, that coolant can seep into the heater core and clog it.

How to unclog a heater core

If your car’s heater isn’t working, there’s a good chance that the issue is with the heater core. A clogged heater core can prevent heated coolant from circulating through the core, which in turn prevents heat from being produced.

There are a few ways that you can unclog a heater core, but the most effective way is to flush it out with a solution of vinegar and water. Vinegar is an acidic substance that will break down any deposits that are clogging the core, and the water will help to flush them out.

To do this, mix together equal parts vinegar and water and pour it into the radiator. Start the engine and let it run for a few minutes so that the solution can reach the heater core. Then, turn off the engine and let it cool down before opening up the radiator cap and draining out the solution.

Once you’ve done this, you should notice an improvement in your car’s heating performance. If not, then you may need to replace the heater core altogether.

How to prevent a heater core from clogging

A clogged heater core can cause your car’s engine to overheat, and in some cases, lead to engine failure. The best way to prevent your heater core from clogging is to have it flushed and replaced every 30,000 miles or so. You can also help prevent clogs by using a good quality antifreeze/coolant in your car.


There are a few methods that you can use to unclog your heater core, but the most effective method is to flush it with vinegar. Vinegar is a natural cleaning agent that will break down the build-up in your heater core and allow it to function properly again. If you have any questions about how to unclog your heater core, feel free to leave them in the comments below and we’ll be happy to help.