Semi-automatic and prosumer machines

Should Your Next Espresso Machine Be a Heat Exchanger or a Dual Boiler?

Published · By the Espresso Shortlist editors · Prices and specs as of that date, from the pages under Sources

Summary

A heat exchanger machine has one boiler, kept hot for steam, with the brewing water passing through a separate path inside it. A dual boiler machine gives the espresso and the steam each a boiler of their own. Both let you brew and steam without waiting for one boiler to change temperature. Among the four machines below, the one heat exchanger, Lelit's MaraX, is also the narrowest, and the dual boilers differ more in controls and plumbing than in the basic layout.

Four machines by the numbers

Lelit MaraXRancilio Silvia Pro XBreville Dual BoilerLelit Bianca
LayoutHeat exchangerDual boilerDual boilerDual boiler
Boilers1.8 L boiler with a stainless steel heat exchanger0.3 L coffee, 1 L steamSteam boiler 950 ml; espresso boiler size not stated0.8 L coffee, 1.5 L steam
Water2.5 L tank2 L tank2.5 L tank2.5 L tank, or a water line with direct drain
Width22.5 cm25 cm37.9 cm29 cm plus 8 cm for the side tank
Weight18.5 kg20 kgNot stated27.2 kg
US price$1,699.95Not listed$1,599.95 (out of stock)$2,999.95

What the heat exchanger has to solve

In a heat exchanger, the boiler sits at steam temperature and the brewing water borrows heat from it on the way to the group. Lelit's description of the MaraX names the problem. Its "double probe HX system with thermosyphon circulation" is meant to keep the brewing temperature steady, "avoiding the overheating typical of classical HX systems." The owner picks Xmode coffee or Xmode steam and one of three temperature settings, Warm, Hot or Extra Hot.

What the second boiler buys

On the dual boilers, the coffee boiler's temperature is set directly. Rancilio puts a PID controller in each of the Silvia Pro X's boilers and adds "soft infusion," low-pressure wetting of the coffee adjustable from 0 to 6 seconds. Breville heats the Dual Boiler's group head as well as its PID-controlled espresso boiler, and says the machine brews and steams at the same time, with one limit in its manual: "You cannot run hot water and extract espresso at the same time." It reaches its default 200°F in about 10 minutes.

The Bianca's extra is a paddle on the group. Lelit says that as the paddle turns, "the water flow on the coffee changes as well, until the highest possible pressure is reached," and a gauge on the group shows the pressure. Lelit lists a water supply and direct drain connection for it, and at 27.2 kg it outweighs the MaraX by almost 9 kg.

Shopping for one? Shop semi-automatic machines →

Sources

  1. Lelit — MaraX PL62X
  2. Lelit — MaraX technical sheet
  3. Lelit USA — MaraX
  4. Rancilio — Silvia Pro X
  5. Rancilio — Silvia Pro X specifications
  6. Breville — the Dual Boiler (BES920)
  7. Breville — Dual Boiler instruction book (BES920)
  8. Lelit — Bianca PL162T
  9. Lelit USA — Bianca

We have not tested these products. Specs, prices, stock and terms are as published on these pages on the date above and can change; check the manufacturer or retailer before you buy.

More semi-automatic and prosumer machines guides

Semi-automatic and prosumer machinesHow Much Should Your Breville Espresso Machine Do for You?Breville's US lineup reads best as a ladder of help. The Bambino models need a separate grinder, the Barista Express and Barista Pro grind for you but…Read the guide →Semi-automatic and prosumer machinesWhat Do You Get for the Extra $200 on a Bambino Plus?Mostly a steam wand that textures milk on its own. The Bambino ($299.95) and Bambino Plus ($499.95) brew the same way, with a 54 mm portafilter, an 18…Read the guide →Semi-automatic and prosumer machinesWhat Does a Prosumer Espresso Machine Add, and What Does It Cost You?Makers don't use "professional" as a class of machine. The word turns up on parts, as in Breville's "Professional 58mm stainless steel portafilter."…Read the guide →Semi-automatic and prosumer machinesWhat Separates One $100 to $150 Espresso Machine From Another?On a listing they look alike. A new CASABREWS CM5418 is $139.99, Gevi's compact ECMG0 is $139.99 marked down from $199.99, and Chefman's CraftBrew is…Read the guide →Semi-automatic and prosumer machinesHow Different Are the Gaggia Classic E24, Rancilio Silvia, and Profitec GO?All three brew and steam from a single boiler, so the real split is in the controls. The Gaggia Classic E24 and the Rancilio Silvia run on switches…Read the guide →Semi-automatic and prosumer machinesWhat Are You Getting With a GE Profile or Café Bellissimo Semi-Automatic Espresso Machine?Both are semi-automatic machines that grind their own beans, run a 15-bar pump, froth milk with steam, and connect to Wi-Fi through the SmartHQ app…Read the guide →Semi-automatic and prosumer machinesHow Much of the Espresso Does Each Smeg Machine Leave to You?Three of Smeg's current US machines split the work three ways. The ECF03 is a manual machine with a 58 mm portafilter and no grinder, so you grind…Read the guide →Semi-automatic and prosumer machinesWhat Makes an Espresso Machine Commercial, and Would One Work at Home?The difference shows up first in the electrical supply. La Marzocco's two-group Linea Classic S, a café machine, lists 208 to 240 volts and a 30-amp…Read the guide →Semi-automatic and prosumer machinesHow Does Meraki's All-in-One Machine Compare With a Fellow Series 1 and Opus 2?Fellow sells its Espresso Series 1 with an Opus 2 grinder as a kit for $1,559.90. The Meraki lists at $1,999, or $1,799 on sale, with the grinder…Read the guide →Semi-automatic and prosumer machinesWhich Specs Matter When You Compare Semi-Automatic Espresso Machines?Three lines on the spec sheet change the morning routine most: how the machine heats, whether you can set the brew temperature, and what the pressure…Read the guide →

All semi-automatic and prosumer machines guides · All guides and search