Thermoblocks Vs. Thermocoils
Several years ago we offered a description of thermoblock espresso machine heating elements. You can find that post here!
A thermoblock is a type of heating element commonly found in home espresso machines. Unlike commercial machines, which feature a boiler, many home machines simply pull water through a heating element for brewing and steaming. Thermoblocks are heating elements of this type that come in a variety of shapes and sizes. In these machines, water travels through a heated block of metal. The water heats up as it passes through the block, preparing it for steaming or brewing. By altering the temperature and flow rate through the block, temperatures for each application can be met. The result is a relatively inexpensive method for heating water for espresso brewing and steaming.
The downside to thermoblocks is that they can lake consistency and longevity. While a high quality thermoblock espresso machine can be nearly commercial grade, cheaper versions exist as well. Ultimately, thermoblocks are a good option for home espresso heating, but newer thermocoils continue to see more use.
Thermocoil heating elements function similarly to thermoblocks. These elements still pull water through the heating element. The difference is that instead of pulling the water through a multiple piece chamber, they use a tube. These tubes are usually made out of copper or another metal. Because the water circulates in the chamber more thoroughly, these heating elements are generally more consistent. While you still have to allow time for temp changes from steaming to brewing, overall they are usually faster too.
On top of this, thermocoils tend to last longer. Because the water circulates in a closed tube, they tend to be less prone to leaks and failures. The best part is that as thermocoil technology evolves, the price is coming down. The result is even better home espresso than you could get several years ago!