What is a Thermoblock?

A thermoblock or thermocoil takes water from the reservoir in an espresso machine and heats it on the fly, versus heating up a full boiler of water. This technology is commonly seen on home espresso machines, where it manages either the brew function, steam function or both. The benefit of a thermoblock is that it doesn’t take as long for your machine to heat up for either brew or steam; however, the drawback can be that your temperature for brew or steam is not quite as consistent as you might like.

Gail introduces us to a few different varieties of thermoblocks/thermocoils and shows how they compare to a standard boiler (specifically, the internals of the Breville Dual Boiler).

Special thanks to Breville for providing the sample internals for this video!

15 comments for “What is a Thermoblock?

  1. Paul
    June 8, 2012 at 12:17 pm

    What makes the thermoblock go tick-tick-tick (or wham-wham-wham) as it puts water/steam out?

    • Kat
      June 8, 2012 at 12:33 pm

      The pump pulling water from the reservoir and moving it through the thermoblock.

      - Kat

  2. David
    June 8, 2012 at 6:08 pm

    Wow thanks for the tutorial!!!!

  3. Maureen Luby
    June 12, 2012 at 1:56 pm

    I have an older model expresso machine from Starbucks, it is no longer available. I believe that the problem with my machine is the Thermoblock coil. Can these coils be repaired? The machine I have has not been used all that much so this should not have happened. Please can you give me advice on this issue? thank you, m.luby.

    • Kat
      June 13, 2012 at 9:23 am

      The Starbucks Barista machines were a variety of private label espresso machines that are still available under their original manufacturer brand. Most often they were Saeco semi-automatics (either the Aroma or the Via Venezia) or Saeco Superautomatics (very similar to the Incanto) and they can be repaired. What’s going on with the machine?

      - Kat

  4. Paul
    November 14, 2012 at 2:10 am


    • Kat
      November 14, 2012 at 8:34 am

      It depends on the model; the 840XL and the newer Barista Express models have the thermocoil; older models have the two part design.

      - Kat

  5. Thomas
    January 3, 2013 at 8:20 pm

    Hi Kat,

    Thank you for the video, I really appreciate it. If I would like to purchase a thermocoil like that, where would i go to get one? And what type of pumps would I need to get to pump water?

    Thank you so much!!!


    • Kat
      January 4, 2013 at 9:57 am

      I don’t know where you’d purchase one separately; these are manufactured specifically for Breville wherever they produce their machines. I doubt they have them available for general sale as it’s a tech advantage for their machines over other models.

      - Kat

  6. Sabrina
    November 21, 2013 at 11:24 am

    Hi Gail!
    Do you have any video with how do these units measure the water volume? Do they count electrolytes, or just knowing the debit it measures the timeā€¦I own BES870 (thermo coil)

    • Kat
      November 25, 2013 at 8:29 am

      Are you talking about the volumetric programming? If so, then it actually counts the number of rotations on the flow meter.


  7. Sergio
    November 13, 2014 at 8:09 am

    Is there a way to find the thermoblock just by itself?

    • November 14, 2014 at 2:39 pm

      Sorry, but I’m not quite sure what you’re referring to. Is this for a specific machine or project? That will help me answer the question.


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