Block Heater Vs. Coolant Heater – What’s The Difference?

Block heaters and coolant heaters are two common devices used to warm up a vehicle's engine in cold weather. Although both serve a similar purpose, they operate differently and offer unique benefits. For this post, we researched the differences between the two, and how they impact engine performance in cold weather conditions. This is what we found out. 

A block heater warms up the engine oil and block directly, while a coolant heater warms up the engine coolant, which in turn warms up the engine block and oil. Both types of heaters help to reduce engine wear and tear caused by cold starts, but coolant heaters are generally more efficient.

Continue reading as we dive into more details about block heaters and discuss additional related topics.

Comparison between block heater and coolant heater, Block Heater Vs. Coolant Heater: What's The Difference?

Block Heaters Vs. Coolant Heaters

Block heaters and coolant heaters are devices used to warm up a vehicle's engine in cold weather. However, they work in slightly different ways.

A common type of block heater has an electric heating element that is installed directly into the engine block. It warms the engine block and the oil, which helps to reduce engine wear and tear caused by cold starts. The block heater needs to be plugged into an external power source to operate.

On the other hand, a coolant heater (also known as a circulating heater) is installed in the engine's cooling system. It heats the engine coolant, which in turn heats the engine block and the oil. 

Coolant heaters are typically more efficient than block heaters because they warm up the entire engine and not just the oil. Coolant heaters can also be either electric or fuel-powered, while block heaters are generally only electric.

Below is a more detailed explanation of their differences

Block Heater

Benefits of a block heater include:

  • Reduced engine wear and tear
  • Improved fuel efficiency
  • Easier cold weather starting
  • Reduced emissions

Coolant Heater

Benefits of a coolant heater include:

  • Faster warm-up time
  • Improved engine performance
  • Reduced emissions
  • Extended engine life

Check out this block heater on Amazon.

In summary, both block heaters and coolant heaters serve the same purpose, but they operate in slightly different ways and have different benefits.

Some cars may come with a block heater already installed. To identify the type of heater you may have in your car, look at the manufacturer's specifications or consult with a mechanic. .

Check out this coolant heater on Amazon.

Heater Maintenance Tips

Here are some maintenance tips for block heaters and coolant heaters:

Block Heater Maintenance Tips:

  1. Inspect the block heater cord for any signs of damage or wear regularly. If you notice any damage, replace the cord immediately.
  2. Keep the block heater cord and plug clean and free of debris.
  3. Only use a block heater for a few hours before starting the engine. Leaving it on for too long can damage the engine or the block heater itself.
  4. Store the block heater cord neatly to avoid tangles or kinks that could cause damage.

Coolant Heater Maintenance Tips:

  1. Regularly check the coolant heater for signs of leaks or damage. If you notice any issues, have the coolant heater inspected by a mechanic.
  2. Make sure the coolant heater is properly grounded to avoid electrical issues.
  3. Only use the coolant heater for a few hours before starting the engine. Leaving it on for too long can cause overheating or damage to the coolant heater itself.
  4. Replace the coolant regularly according to the manufacturer's recommendations. Old or contaminated coolant can cause corrosion and other engine problems.

Power cord of block heater connected to car

When used correctly, a block heater will not damage the engine. However, there are some potential risks associated with block heaters that can cause damage to the engine if they are not used properly.

Electrical issues

Block heaters require an external power source, and if the wiring or electrical connections are faulty, it can cause damage to the engine or even start a fire. It is important to inspect the wiring and connections regularly to ensure they are in good condition.

Improper installation

If a block heater is not installed correctly, it can cause damage to the engine block or other components. It is important to have a professional install the block heater to ensure it is installed correctly and does not cause damage.

Overall, block heaters can be a useful tool in cold weather conditions to improve engine performance and reduce wear and tear. As with any device, it is important to use it properly and follow the manufacturer's instructions to prevent damage to the engine.

It is generally safe to start your car with a block heater plugged in, but it is not recommended to leave the block heater on when you start the engine.

The recommended maximum duration for keeping the engine block heater plugged in is four hours. Once you are ready to start the engine, you should unplug the block heater to avoid overheating the engine or damaging the block heater.

It is also important to note that the block heater should not be used as a substitute for regular engine maintenance, such as oil changes and tune-ups.

While a block heater can help to reduce wear and tear on the engine, it is still important to keep up with regular maintenance to ensure your car is running properly.

What Are The Disadvantages Of A Block Heater?

Block heater cable plugged into a vehicle

While block heaters have many advantages, such as helping to reduce engine wear and tear and improving fuel efficiency, they also have a few disadvantages, including:


Block heaters can cost up to $120, which may be a disadvantage for some vehicle owners.

Energy consumption

Block heaters require electricity to operate, which can lead to increased energy consumption and higher electricity bills.

Fire hazard

Block heaters can pose a fire hazard if the cord is damaged or the device is not used properly.

What Are The Disadvantages Of A Coolant Heater?

Installation of additional auxiliary heater of the car

While there are many advantages to using a coolant heater, there are also some disadvantages to consider as well. Some of them are even similar. These are as follows:


One of the biggest disadvantages of a coolant heater is the cost. While some models are relatively inexpensive, others can be more than $100. Additionally, the cost of electricity or fuel required to operate the heater can add up over time.


Like any mechanical device, a coolant heater requires regular maintenance to ensure that it continues to function properly. This can include cleaning the unit and checking the electrical connections.

Failure to maintain the heater can result in decreased efficiency and an increased risk of malfunction.


Coolant heaters may require a fair amount of technical expertise to operate. This means that they may not be a good option for DIY enthusiasts or those who are not comfortable working with automotive systems.

What Can I Use Instead Of A Block Heater?

Block heater cable plugged into a car on a cold winter day to warm engine

If you live in a cold climate and don't have a block heater, you can try several alternative methods to help your engine start in the cold:

Battery warmer

A battery warmer is a small electric blanket that wraps around your car battery and keeps it warm. This can help your car start in cold weather.

Oil pan heater

An oil pan heater is a small electric heating pad that you can install on the bottom of your engine's oil pan. This keeps the engine oil warm and helps the engine start more easily.

Garage or carport

Parking your car in a garage or carport can help protect it from the cold and prevent it from getting too cold. 

Synthetic oil

Using synthetic oil can help your engine start more easily in cold weather. Synthetic oil flows more easily than conventional oil at low temperatures, which can help reduce engine wear and tear.

In Review

Block heaters and coolant heaters are two different devices used to warm up a vehicle's engine in cold weather. While block heaters warm up the engine block and oil directly, coolant heaters warm up the engine coolant, which then warms up the engine block and oil.

Both types of heaters offer benefits, but coolant heaters are generally more efficient due to their ability to warm up the entire engine.

Have more related queries? Check out some of our other posts below!

Why Does My Block Heater Keep Burning Out?

Oil Pan Heater Vs. Block Heater: What’s The Difference?

Can Engine Coolant Freeze? [And At What Temperature]

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