P Patrick Cotter

Thermoblock Vs. Boiler Espresso Machines

May 27, 2024 · coffee 101 · educational · espresso · videos
Thermoblock Vs. Boiler Espresso Machines

There are three things that you absolutely need in order to brew espresso. The first, ground coffee, is pretty obvious! Second, you need pressure, and third, you’ve got to have hot water. Today we’re going to look at that third piece, and how espresso machines generate the hot water that they use for brewing. As you’re probably aware, many espresso machines use pressurized boilers to heat up their water, similar to what you’d find in many other heating applications. Another type of heating element that lots of newer machines use is a thermoblock, which functions much differently than a boiler. We’re going to talk about how they differ here!

What’s a Boiler?

A boiler is a component that holds water inside and evenly heats it. This results in a volume of hot water that is ready to go for brewing and/or steaming. There are several different types of boiler designs, from traditional boilers that function exactly as above, to heat exchangers that have a pass-through pipe that rapidly heats a smaller amount of water on demand (usually for steaming while brewing). There are also many machines that contain multiple boilers, with one dedicated to brewing and the other dedicated to steaming or hot water. Different boilers are made from different materials, come in different sizes, and may use different methods to heat and control temperatures.

While there are differences across boiler designs, they generally have similar characteristics. Boilers provide evenly heated water that should provide good consistency. They also will usually work with an even power draw, as they constantly heat the water to a specific temperature. The downside is that they can take some time to come up to temp, and if you “outrun” the boiler (as in, empty it by brewing/steaming faster than it can heat more water) then you’ll have to wait for it to recover between drinks. This is pretty tough to do on higher end machines, as their volumes and recovery times are usually beyond what you could need in a home brewing environment. So how does a thermoblock differ?

What’s a Thermoblock?

A thermoblock is a (relatively) new approach to water heating for espresso machines. While thermoblock heated machines have existed for decades at this point, they are newer technology compared to the more traditional boilers that have existed for well over a century. A thermoblock is what it sounds like - a highly heated block with a small pipe/tube running through it that water passes through. The high heat of the block rapidly heats up water running through it to provide on-demand hot water for brewing and steaming. 

What this means is that thermoblock machines can come up to temp very rapidly. Many thermoblock machines can go from idle to brew temps in a minute or less. This is very convenient if you are in a rush, or if you need to brew multiple drinks. Some thermoblock machines even have multiple blocks, with one for brewing and one for steaming. These machines are some of the fastest out there for making things like lattes and cappuccinos. The downside is that a single thermoblock machine will struggle to steam and brew at the same time (if it’s an option at all). These machines also spike in their power draw, with some requiring higher capacity circuits to accommodate the increased power needs.

Which is Right for Me?

Which kind of machine is right for you really depends on your needs. If you want that traditional cafe workflow and don’t want to worry about increased power needs, then a traditional boiler based machine is probably a better fit for you. If you are looking for something entry level and want to brew your drinks without waiting for heat up time, check out some thermoblock options. To see some of those options and learn more you can watch our video below!


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