Espresso Machine Types

The way a machine heats and manages water shapes everything about how it brews and steams. Most pump machines fall into three boiler architectures, with the manual lever standing apart as a mechanical category.

Single boiler

One boiler heats water for both brewing and steaming. Because espresso wants roughly 90-96°C and steam wants ~130°C+, you cannot do both at once: you brew, flip to steam mode, and wait 60-90 seconds for the boiler to climb before frothing milk. It's the cheapest and most compact approach, and perfectly fine if you drink mostly straight espresso and only occasionally steam milk.

• Pico — entry single-thermoblock, no PID, pressurized baskets. Brew-then-steam.
• Solo — single boiler with PID for stable brew temperature, 58mm. Brew, then wait 60-90s to steam.

Heat exchanger (HX)

A single boiler is held at steam temperature, and cool brew water is drawn on demand through a heat-exchanger tube passing inside that boiler. This lets you brew and steam simultaneously with strong steam power. The trade-off: brew-water temperature drifts upward as the machine idles, so you pull a short cooling flush (2-4s) to reset it before the first shot. Brew temperature is less precise than a PID boiler.

• Flux — HX design; simultaneous brew and steam, mid price.

Dual boiler

Two independent boilers, each PID-controlled: one for brew, one for steam. You get simultaneous brew and steam and precise, adjustable brew temperature with no cooling flush. It's the most capable and most expensive pump architecture.

• Duo — dual PID boilers, adjustable brew temp.

Lever (mechanical)

A separate category. A manual spring lever generates pressure — no electric pump. Pulling the lever compresses a spring that delivers natural pre-infusion followed by a declining pressure profile. Steam-capable and deeply hands-on.

• Lever — spring-lever machine for the enthusiast.

Comparison

Ready to pick? See the machine buying guide, review espresso fundamentals, and check accessory compatibility.