Espresso machine boilers: What you need to know 

When you decide to look at machine specifications, you may see words, such as single boiler, dual boiler, and many more. You should note that a boiler is a part of an espresso machine that is responsible for heating up the brew water and offering steam to the steam wand. In most cases, brewed water which is utilized for extraction is usually about 90℃. 

But these boiler types tend to differ when it comes to the way each one prepares the water temperatures. You need to consider the type of a boiler you need to purchase, especially for fully or semi-automatic machines. A manual machine doesn’t have a boiler, and you don’t have to worry about how the super-automatic machine functions. This article discusses espresso machine boilers.

Single boiler

A single boiler uses one boiler, meaning it can raise and lower the water temperature depending on whether you want to steam or brew. But a single boiler usually has some drawbacks. You cannot brew and steam at the same time and there is a wait time that is there between brewing and steaming. Remember that these drawbacks are due to the structure of the boiler. Because there is a single boiler, various temperatures cannot be offered simultaneously. 

As a result, this type of boiler may not be a great option for certain places, such as cafes where you must prepare many drinks in a short period. On the other hand, you can use a single boiler for home use. Because of its simplicity, it’s usually the lowest cost boiler available in the market. You may need to compromise timing as you need a lot more time so that you can prepare the drinks, though it may not be an issue if you just want a couple of cups each day. 

It’s worth mentioning that when you decide to make several milk drinks with a single boiler, it’s quicker to pull the shots you want then adjust the temperature so that you can steam the milk  


For this reason, this type of boiler is not a good option for places like cafes where you have to prepare many drinks in a short period. This is better than alternating between brewing and steaming. This helps to lower the number of times you have to change the boiler temperature.

Dual boiler

With a dual boiler, it utilizes two independent boilers to offer the brew water and steam. This means that it utilizes a single boiler for the two temperatures. In this way, it allows you to pull a shot and steam milk. This improves the work flow significantly, especially for busy environments. 

The good news is that there is no structural problem to this method, though having two boilers can increase the cost of the machine. 

There is no structural disadvantage to this scheme, but having two boilers can increase the cost of the machine. Regardless of the cost, you just need to figure out how you intend to utilize the machine. This can help you to determine whether or not a dual boiler espresso machine is worth an additional investment. If you desire to regularly serve your customers or friends, then it can be worth it. 

Heat exchangers

Most heat exchanger machines often have some features that are similar to dual boilers. A heat exchanger boiler can pull shots as it is steaming milk simultaneously. Therefore, a heat exchange boiler can have a single boiler as well as a pipe that runs through or even close to the boiler.

You should remember that the boiler is usually at boiling temperature so that it can provide steam. And, the pipe runs cold water to begin with, though as the water goes through the pipe it tends to get heat from the boiler and stops at the group head with the right temperature for brewing. 

As a result, heat exchanger machines can simultaneously brew and steam with just a single boiler. In most cases, it needs fewer components than a dual boiler which usually places the cost of a heat exchanger slightly lower than a dual boiler. This can also depend significantly on the type of machine you want to purchase.

Because of the mechanism of a heat exchanger, the brew water can sometimes get overheated once you leave it in idle. This means that you need to flush the group head so that you can remove the over-heated water before you begin to pull your shot. 

Besides this, your brew temperature can be indirectly controlled by the temperature of the boiler. Therefore, if you intend to have a lower temperature, then you must lower the temperature of the boiler. This can in turn provide you with less steaming power. 

No doubt, the mechanism of giving the right brew temperatures is often more involved than using a dual boiler. Hence, you can usually get a more stable temperature control when you use a dual boiler and the chance to independently control the temperature of the brew and steam pressure. 

That said, most manufacturers of heat exchangers have focused on improving temperature stability. Therefore, it can make sense to choose a heat exchanger and a dual boiler if you are considering making the purchase. 

Modern boilers of the espresso machines are made up of different materials. The materials can be varied, and you can even find some that have a combination of materials. Before you decide to purchase a boiler, you need to consider the composition of the materials.  

In conclusion, a single boiler can be suitable for home use, though it cannot brew and steam simultaneously. On the other hand, a dual boiler can brew and steam simultaneously, and it has great control of temperature. Alternatively, you can choose a heat exchanger which can simultaneously brew and steam, but you need to keep watch of the temperature stability. 

Therefore, if you intend to purchase an espresso machine for your large family, a heat exchanger or a dual boiler can be a suitable option. And, if you want to upgrade over time, it’s a good idea to secure a good boiler right away.