Pros and cons of bypassing the heater core

There are several different pros and cons to bypassing the heater core. The most common are listed in the information provided below.


  • Heater Core is no longer working
  • The vehicle owner resides in a tropical country (no heat is required for cold seasons).
  • Driver prefers to skip adding additional coolant into their system.
  • More efficient flow, no additional routing to complete the heating cycle.
  • Reduces the chance of the engine overheating
  • Prevents unnecessary coolant leaks
  • Eliminates the need for costly heater core repairs


  • The car will no longer have any heating capacity in the cabin of the car
  • Defogger completely useless

What is the role of the heater core?

A heater core can be described as a radiator-like component that is normally located inside the dashboard of the cabin. Its primary purpose is to heat the vehicle’s cabin, specifically during the winter season.

It does its job by circulating the coolant from the engine through various tubes and parts. It is also important to note that the air conditioning system and the defroster are linked to the heater core.

Therefore, when this part of the heating system does not function properly, the temperature in the cabinet will not heat up.

Is a heater core necessary?

The answer to this question is dependent on several different factors. As mentioned above, every car owner can make their own individual decision.

Because the heater core is designed to send the heat from the engine into the cabin of the car, the function it serves can be optional.

For example, if the automobile owner lives in a geographical location that does not have cold weather, heat in the cabin of the car may not be necessary.

Therefore, bypassing the heater core may be beneficial in numerous ways, including saving money on the cost of buying coolant.

On the flip side, if the car owner lives in a location that gets very cold during the winter month, the heater core is essential to keeping warm and safe. So, the decision that is made is no longer optional.

Additionally, every car owner should know that the heater core does not only affect the source of heat in the cabin. The heater core is also needed for keeping the windshield in the vehicle clear of fog, too.

This is because the heater core is designed to serve as a defogger as well. So, without this function in the vehicle, the driver cannot keep their windshields or rear glass clear enough to drive safely on the highway or the city streets.

In essence, the defogger in the car will become absolutely useless.

Does the heater core have anything to do with the air conditioning?

In general, no. Yet, the only related connection between both the heater core and the air conditioning system is the extra efficiency in the route that it will take.

For instance, if the heater core is removed completely, the flow of the coolant doesn’t need to go an additional route.

Otherwise, in most cases, the heating system relies solely on hot coolant from the engine, while the air conditioning system uses refrigerant to cool the cabin of the car.

Each of these two systems is separate and has been designed to function independently without adversely affecting the performance of the engine.


There are both pros and cons to bypassing the heater core in a car today. So, it is important to do your research before making these types of modifications to your vehicle.

Even though there may be more advantages than disadvantages to removing the heater core, there are numerous other factors involved.

Specifically, if you are making a decision based on the location that you live in, you need to know all of the ramifications involved.

Typically, if you do not have a need in a car to keep warm on cold winter days, you may be able to benefit from bypassing the heater core.

Contrariwise, if you need the capabilities of a defogger to keep your windshield and rear glass clear, the heater core should not be bypassed at any time.

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