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Heater Core

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When you're driving on a cold, winter night, a busted heater core would be the last that you need. If this component malfunctions, you'd have to endure driving without proper ventilation, and this can be extremely dangerous. Here's a quick guide on everything that you need to know about faulty heater cores and how to repair them.

Symptoms of a Bad Heater Core

Prevention is always better than cure, so it's good to diagnose a broken component before it causes you troubles on the road. Here are some of the most common symptoms that you have to watch out for.

1. No heat

If you've already turned the engine on for quite some time yet the heater fails to produce any amount of heat or warmth, then you might want to take a look at your heating system. This is unusual because the heater is supposed to work as soon as the engine coolant has started to circulate.

2. Leak

Cracked heater cores or heater hoses can cause engine coolant to leak inside the vehicle or in the engine compartment.

3. Erratic temperature

This particular symptom is characterized by the constant temperature fluctuation in your vehicle's cabin from cold to hot and vise versa.

4. Noises

Heaters usually operate with little or no noise, so if you start to hear grinding or clanking sounds after start up, check your heating system right away.

Flushing a Heater Core

After years of continued use, heater cores need to be flushed because they can accumulate dirt, grime, and rust, which can decrease their normal working capacity. Here's how:

Step 1: Remove the plug at the bottom of the radiator to drain the coolant out.

Step 2: After draining the coolant, remove the inlet hose from the core.

Step 3: Next, get the heater core filled with an acid-base solution to remove any clogged up debris. Leave it for about 30 minutes.

Step 4: After that, unplug the outlet hose and attach a water hose to the inlet hole. Let water run through the core and allow it to come out through the outlet hole.

Step 5: Reattach the inlet and outlet hoses and refill the coolant reservoir. Lastly, start your vehicle and see if the heater works fine.

Repairing a Heater Core

Here's a short and basic guide on how to replace faulty heater cores. Note that some of the steps may not be applicable depending on the car that you have.

Step 1: To begin, raise the front side of the vehicle using a jack and support it using jack stands.

Step 2: Next, remove the plug at the bottom of the radiator to drain the antifreeze and coolant.

Step 3: If your vehicle has an AC heater drain tube, you need to remove it as well.

Step 4: Put a drain pan underneath to catch the remaining antifreeze from the hoses and core. Remove the hoses by loosening their clamps.

Step 5: Lower the vehicle and remove the old heater core. Once you've taken it out, clean the area before installing the new one. After that, reinstall the hoses that you removed earlier and refill your coolant and antifreeze.

Heater Core Articles

  • Heater Core Failure and Repair

    When you\'re driving on a cold, winter night, a busted heater core would be the last that you need. If this component malfunctions, you\'d have to endure driving without proper ventilation, and this can be extremely dangerous. Here\'s a quick guide on everything that you need to know about faulty heater cores and how to repair them.

    Symptoms of a Bad Heater Core

    Prevention is always better than cure, so it\'s good to diagnose a broken component before it causes you troubles on the road. Here are some of the most common symptoms that you have to watch out for.

    1. No heat

    If you\'ve already turned the engine on for quite some time yet the heater fails to produce any amount of heat or warmth, then you might want to take a look at your heating system. This is unusual because the heater is supposed to work as soon as the engine coolant has started to circulate.

    2. Leak

    Cracked heater cores or heater hoses can cause engine coolant to leak inside the vehicle or in the engine compartment.

    3. Erratic temperature

    This particular symptom is characterized by the constant temperature fluctuation in your vehicle\'s cabin from cold to hot and vise versa.

    4. Noises

    Heaters usually operate with little or no noise, so if you start to hear grinding or clanking sounds after start up, check your heating system right away.

    Flushing a Heater Core

    After years of continued use, heater cores need to be flushed because they can accumulate dirt, grime, and rust, which can decrease their normal working capacity. Here\'s how:

    Step 1: Remove the plug at the bottom of the radiator to drain the coolant out.

    Step 2: After draining the coolant, remove the inlet hose from the core.

    Step 3: Next, get the heater core filled with an acid-base solution to remove any clogged up debris. Leave it for about 30 minutes.

    Step 4: After that, unplug the outlet hose and attach a water hose to the inlet hole. Let water run through the core and allow it to come out through the outlet hole.

    Step 5: Reattach the inlet and outlet hoses and refill the coolant reservoir. Lastly, start your vehicle and see if the heater works fine.

    Repairing a Heater Core

    Here\'s a short and basic guide on how to replace faulty heater cores. Note that some of the steps may not be applicable depending on the car that you have.

    Step 1: To begin, raise the front side of the vehicle using a jack and support it using jack stands.

    Step 2: Next, remove the plug at the bottom of the radiator to drain the antifreeze and coolant.

    Step 3: If your vehicle has an AC heater drain tube, you need to remove it as well.

    Step 4: Put a drain pan underneath to catch the remaining antifreeze from the hoses and core. Remove the hoses by loosening their clamps.

    Step 5: Lower the vehicle and remove the old heater core. Once you\'ve taken it out, clean the area before installing the new one. After that, reinstall the hoses that you removed earlier and refill your coolant and antifreeze.