Coffee 101: Thermoblock vs. Boiler

Quick Summary

Thermoblock vs. Boiler: What to Choose? Thermoblocks and boilers are two types of heating mechanism for espresso machines. The benefits of a thermoblock vs. boiler differ in purpose, speed, and heat retention. A thermoblock can produce a small amount of coffee very quickly. However, boilers are usually found in large, industrial coffee machines.

When it comes to a thermoblock vs. boiler espresso machine, boilers are becoming more popular. Thermoblocks have a few flaws and don't tend to last as long as boiler-based machines.
Both type of devices benefit from having a PID: What is a PID Controlled Espresso Machine?

Thermoblock: Pros and Cons

Best Thermoblock Espresso Machine

Best Thermoblock Espresso Machine

A thermoblock is made of two metal blocks welded together. Water flows through passages within the block, constructed like a maze. By the time the water exits the thermoblock, the water is appropriately heated.

You can find thermoblocks in many smaller coffee makers, including those commonly found in homes, offices, and most automatic models. Newer models feature a thermocoil, which offers better heating. Read more: 
Thermocoil vs. Thermoblock

The Good

Thermoblock coffee machines are affordable and available in compact sizes. Due to its small size, thermoblocks can heat up water very quickly, with "flash-heat" as water flows through the maze-like passages. Between the thermoblock vs. boiler, thermoblocks help you save energy. You don't need to turn on the machine until you need it.

They can be made from a variety of metals, like steel, aluminum or brass. Each metal has different advantages. Brass is less likely to scale, but aluminum is better at retaining heat.

Thermoblock models can also produce consistent, high-quality dry steam by simply increasing the heat until the water becomes steam.

The Bad

Since thermoblocks use narrow passages to heat water, they are prone to blockages. Certain metals like aluminum might scale, the pieces can clog your machine. Thermoblocks are composed of two welded pieces, which makes them more likely to leak or break than other models.

Although it heats water quickly, the water heat isn't always consistent. Thermoblock machines tend to last an average of three to five years.

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Boiler Espresso Machine: Pros and Cons

Best Boiler Espresso Machine

Best Boiler Espresso Machine

Boiler espresso machines are great for commercial or industrial use. However, some smaller models have also begun to incorporate boilers too.

There are a few different types to choose from: single boiler, heat exchange boiler, or twin boiler. The type of boiler you choose depends on the kind of drinks you intend to make.

A single boiler is suitable for making just espresso without milk or steam. Heat exchange boilers have a tube running through the main boiler that heats the water. Twin boilers have two compartments that you can use separately for espresso and steam.

The Good

The greatest benefit of a boiler is its ability to heat and hold hot water, so it's always ready for use. Boiler espresso machines also heat water consistently and maintain your desired temperature.

They are made with metals like copper or stainless steel. This heavy-duty heating mechanism will last you a very long time.

The Bad

The major drawbacks of a boiler-based coffee machine are time, energy and price. Since the boiler heats up a larger quantity of water at a consistent temperature, it can take a while to heat up. You may have to wait up to ten minutes before the water is fully heated.

Boilers cost significantly more than thermoblock models, which is why they are commonly used in commercial settings.

Resources

SCG - What is a thermoblock?
SCG - Different types of boilers