Thermoblock Espresso Machines: Fast Heat-Up, Steam Limits, Which Models Use What

“Thermoblock” rarely appears on the box of the machines that use the idea best. Breville says ThermoJet or Thermocoil, CASABREWS talks about fast heating, and a good many budget listings say nothing at all. So this page does two jobs: it explains what heating on demand gets you, and it shows which word each machine uses. For a look at all four heating types, see single boiler, dual boiler and heat exchanger compared.

Our pick: with a separate grinderAd

Breville

Breville Bambino

A compact machine with a 54 mm portafilter, ready in 3 seconds. The grinder is yours to choose.

Why here: The one we would buy for this routine: ready in 3 seconds per Breville, with a proper 54 mm portafilter, and you choose the grinder.

Best for: Beginners who want to pick their grinder and upgrade it later

• +Ready to start in 3 seconds (Breville)
• +54 mm portafilter, 18 g dose (Breville)
• +Manual steam wand for hand-textured milk (Breville)

• –Needs a separate espresso-capable grinder
• –Breville's product page does not mention PID, though its BES450 instruction book does

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Heating

ThermoJet

Pump, as stated

15 bar

Brew pressure, as stated

9 bar

Portafilter

54 mm

PID

Yes, per the instruction book

Built-in grinder

No

Milk

Manual wand

Price class

Mid-range

Who should buy which?

Your order

• If you want a short wait and will choose your own grinder → Breville Bambino

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• If you mostly drink milk and don't want to learn the wand first → Breville Bambino Plus

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• If you want the grinder in the same body → Breville Barista Express

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• If you make several milk drinks in a row

  See dual boiler machines

The machines side by side

Comparison: Breville Bambino, Breville Bambino Plus, Breville Barista Express, Breville Barista Pro, Smeg EGF03

Comparison	Our pick: with a separate grinderBreville Bambino	Our pick: milk drinksBreville Bambino Plus	Our pick: built-in grinderBreville Barista Express	Breville Barista Pro	Smeg EGF03
Heating	ThermoJet	ThermoJet	Thermocoil	ThermoJet	Double thermoblock
Pump, as stated	15 bar	15 bar	15 bar	15 bar	20 bar and 15 bar, both on Smeg's page
Brew pressure, as stated	9 bar	9 bar	9 bar	9 bar	–
Portafilter	54 mm	54 mm	54 mm	54 mm, per the instruction book	58 mm
PID	Yes, per the instruction book	Yes, per the instruction book	Yes	Yes, per the instruction book	–
Built-in grinder	No	No	Yes, 16 settings	Yes, 30 settings	Yes
Milk	Manual wand	Hands-free or manual	Manual wand	Steam wand	Steam wand, two levels
Price class	Mid-range	Mid-range	Mid-range	Mid-range	Premium
Best for	Beginners who want to pick their grinder and upgrade it later	Latte and flat white drinkers who do not want to learn the wand first	First-time buyers who want one box and no separate grinder to choose	Built-in-grinder buyers who want more grind steps and fast heat-up	Buyers who want the retro look and two heating blocks, after reading the manual
	On Amazon*(paid link to Amazon, opens in a new tab)Ad · paid link · check price & delivery on Amazon	On Amazon*(paid link to Amazon, opens in a new tab)Ad · paid link · check price & delivery on Amazon	On Amazon*(paid link to Amazon, opens in a new tab)Ad · paid link · check price & delivery on Amazon	On Amazon*(paid link to Amazon, opens in a new tab)Ad · paid link · check price & delivery on Amazon	On Amazon*(paid link to Amazon, opens in a new tab)Ad · paid link · check price & delivery on Amazon

The first four columns come from Breville's pages, and the Smeg column from Smeg's US page. A blank row means we have no value, not that the feature is missing. How we compare explains the labels.

What a thermoblock does

A boiler holds water and keeps it hot. A thermoblock, as Seattle Coffee Gear describes it, is a highly heated block with a small pipe running through it, and the water picks up its heat on the way through. There is little water to heat in advance, so the wait is short. Thermoblock and thermocoil machines both heat on demand, and ThermoJet is Breville's printed-circuit version of the idea.

Brewing wants about 200 °F and steaming about 266 °F. That gap is the whole problem. One heater has to get from one number to the other before it can do the next job.

Fast to the first shot. Steam is where you read the small print.

Steam: what to expect

Seattle Coffee Gear says a single thermoblock machine will struggle to steam and brew at the same time, and that some models use separate blocks for each task. It also notes that these machines spike in power draw, and that some need a higher-capacity circuit. Breville's advice for a machine with a single heating element is to brew the shot first, then texture the milk.

How much that costs you in the morning depends on the model. You will often see one fixed wait quoted between shot and steam, and we could find no source for it. Read the manual for yours. We also found no measurement of steam strength across this group, so we won't call the whole category weak. If your routine is one latte, this barely matters. If it's four, a dual boiler solves the problem.

One drink at a time

This class suits a simple rhythm: pull the shot, texture the milk, pour. If a thermoblock leaves you with big bubbles, check your technique and a clean tip first, then think about the machine. Our microfoam page shows what you are aiming for.

What good milk texture looks like

Which machine uses which heater

Note that those times are the makers' own, and they don't all measure the same thing. Breville's “ready to start” and De'Longhi's “ideal temperature” are not the same test, and neither is a measurement of ours. Breville also describes ThermoJet by comparison, claiming it is up to 44.3% more energy efficient than a thermoblock, so the company clearly doesn't see them as identical. For a buyer, they're in the same family: no large tank of hot water waiting.

The models, one by one

Breville Bambino: our pick

Breville lists its ThermoJet heater as ready to start in 3 seconds, a 54 mm portafilter with an 18 g dose, single wall and dual wall baskets, a 15 bar pump with 9 bar extraction, and a manual steam wand. For a machine this small, that is a lot of real control. You pull a shot and steam milk by hand, one after the other, and you can upgrade the grinder later without touching anything else.

The trade-offs are clear. It needs a separate grinder, and there's no shot timer in its feature list as we read it, so bring a scale with one. Breville's product page doesn't mention PID, so we write “not stated.” Our Bambino page covers the details.

Breville Bambino Plus: for milk drinks

The Bambino Plus^* keeps the ThermoJet and adds a hands-free wand with 3 milk temperatures and 3 texture levels, according to Breville. You put the jug on the sensor and it does the texturing, or you steam by hand. It's the easy answer if you want a good milk drink before you've learned to steam, and our Bambino Plus page goes further.

Breville Barista Express: Thermocoil with a grinder

The Barista Express^* uses a Thermocoil and states PID temperature control, with water at 200 °F. It has a built-in grinder with 16 settings and a 54 mm portafilter. PID keeps the heater closer to its set point, though measured stability at the puck depends on the machine. The wider story is on our Barista Express page. One thermocoil is not two boilers, so you still brew and steam in turn. If you want the same grinder idea with more steps and the faster heater, the Barista Pro^* lists 30 grind settings and ThermoJet.

Smeg EGF03: the double thermoblock on Amazon

The Smeg EGF03^* says “Dual Thermoblock” in its title, along with a built-in grinder and a retro look. That's more candid than a budget listing that says “dual boiler.” Smeg's US page lists a double thermoblock with separate coffee and milk circuits and a 58 mm filter holder, and says steam is ready immediately after brewing. It doesn't claim both at once. The same page prints 20 bar and 15 bar for the pump. It's in the premium class, so read the manual before you pay for the word.

Budget machines: read what the listing says

Many budget machines don't name their heater at all. The CASABREWS 5418 PRO^* says “fast heating system,” which points in this direction without proving it. Our CASABREWS page goes through one such range. Our own rule is simple: if the listing doesn't name the heater, we don't name it either.

What to check before you buy

1. The wait you care about. Time to the first shot is the number on the box. Ask how long the wand takes after the shot, and find that in the manual.
2. How you steam. Manual wand or automatic, and whether the wand is strong enough for your milk. The microfoam page above shows what to look for.
3. The portafilter and baskets. A single wall basket lets you work with grind and ratio. Breville says dual wall baskets regulate the pressure regardless of grind, dose or freshness.
4. The grinder budget. None of the compact machines here includes one.
5. The pump number. Leave it out. The 15 or 20 bar on the box is what the pump can reach. Espresso is brewed at about 9 bar.
6. Your outlet. Seattle Coffee Gear notes that power draw can spike. Use the circuit the manual asks for, and ask an electrician if you are unsure.

Mistakes to avoid

• Treating “thermoblock” as a verdict. It describes the heater, not the shot. We found no neutral data that ranks flow heaters against boilers for espresso quality.
• Reading “dual” as two boilers. Budget titles can mean two heating units. Check the manual.
• Comparing start-up numbers from different makers. They don't measure the same thing.
• Skipping the descale. Follow your manual's schedule, and use the water it asks for.

Find your machine

Not sure the heater is your deciding factor at all? These questions start from what you drink.

Our recommendation

If you make one or two drinks at a time and want little waiting, buy the Breville Bambino^* and budget for a good grinder. Choose the Bambino Plus if the wand is the part you'd rather skip, and the Barista Express if you want everything in one body. Several milk drinks in a row is the one case where we'd step out of this group altogether. Our full comparison has the other picks, and the start page sorts them by what you drink.