A PID espresso machine uses an electronic PID controller to hold its boiler at a temperature you set in degrees, instead of relying on a mechanical pressurestat or thermostat that switches the heater fully on and off. The PID reads the boiler temperature continuously and pulses the heating element in measured amounts, so brew temperature stays closer to the set point and you can change it from a display. Below is how that works, why it matters for flavor, how PID behaves on single boiler, heat exchanger and dual boiler machines, and which machines in our range list a PID.
What does a PID controller do?
PID stands for proportional, integral, derivative. It is a feedback control method used widely in industry, temperature regulation included. The controller compares the target value (the set point) with the measured value and treats the difference as an error. It then corrects that error three ways: in proportion to its current size, by the error that has built up over time, and by how fast the error is changing, which helps limit overshoot.
In an espresso machine the measured value is the boiler temperature. La Marzocco explains that the PID keeps reading and modelling that temperature and switches the element on and off in rapid blips, varying the ratio of on time to off time. That controls how much power goes into the boiler, which gives much finer temperature control than simple on/off switching.
PID vs pressurestat
Before PIDs, boiler temperature was controlled by thermostats or pressurestats: small mechanical devices that turn the heater on when the boiler drops below a set point and off again once it gets there. La Marzocco notes that these were not very accurate. The boiler had to cool below the set point before heating resumed, and it kept heating a little past the shutoff point, so temperature swung up and down and was hard to control precisely.
| Pressurestat or thermostat | PID controller | |
|---|---|---|
| How it heats | Heater fully on below the set point, fully off above it | Rapid on/off pulses with a varying ratio |
| Temperature behavior | Swings below and above the target | Held close to the target |
| Changing the temperature | Mechanical adjustment | Set in degrees on a display |
Home enthusiasts were adding PID controllers to their espresso machines by 2001, and La Marzocco says its first machine with a PID as standard launched in 2005. In our range, many PID displays also double as shot timers.
Why brew temperature stability matters
La Marzocco explains that hot water extracts flavor by dissolving soluble compounds in the coffee, and that a higher temperature does more extraction work while a lower temperature does less. Its machines leave the factory set to brew at 200 °F (93 °C), and it suggests higher temperatures for light roasts and lower ones for dark roasts. ECM gives similar advice in its Mechanika VI Slim manual: choose a cooler extraction temperature for darker roasts to reduce bitterness, and a higher one if the coffee tastes too acidic.
That kind of adjustment only works if the machine actually holds the temperature you chose. A PID lets you set a value, repeat it day after day and change it in small steps, so when you are dialing in espresso, a change in taste comes from the grind or recipe rather than from a boiler drifting through its cycle.
PID on single boiler, heat exchanger and dual boiler machines
Single boiler
One boiler does everything, so the PID holds one temperature for brewing and a higher one for steam. ECM’s Classika PID manual shows the defaults: 93 °C for coffee and 130 °C for steam, with the display switching to the steam temperature when you turn steam on. You brew first, then wait for the boiler to heat up for milk. Browse our single boiler espresso machines.
Heat exchanger
A heat exchanger keeps one boiler at steam temperature and heats brewing water indirectly as it passes through the exchanger. The PID controls the boiler, so brew temperature follows the boiler setting rather than being set directly. ECM’s Mechanika VI Slim manual shows boiler settings of 120, 124 and 128 °C producing brew temperatures of roughly 90, 94 and 98 °C after a short flush, and notes that a longer or shorter flush changes the result. Some designs go further: the ECM Mechanika Max can regulate its boiler from the temperature measured at the brew group, in 1-degree steps. Read more in our guide to the E61 group head.
Dual boiler
Separate brew and steam boilers each get their own temperature setting. ECM notes that two boilers let you set brew and steam temperatures independently, and Rancilio describes its current dual boiler design as having two PID controllers, one in the coffee boiler and one in the steam boiler. This is the most direct form of brew temperature control: you set the brew boiler and it holds that value while you steam. Browse our dual boiler espresso machines.
PID espresso machines in our range
These new machines list a PID. Boiler type and PID details come from each listing.
| Machine | Boiler type | What the listing says about the PID |
|---|---|---|
| Profitec GO | Single boiler, 0.4 L | Sets brew temperature, doubles as shot timer; about 1 minute from brew to steam |
| ECM Classika PID | Single boiler, 0.75 L | Controls brew and steam temperature; E61 group |
| ECM Puristika | Single boiler, 0.75 L | PID temperature control; espresso only, no steam wand |
| Profitec Pro 500 PID | Heat exchanger, 2 L | Works with the thermosyphon so routine cooling flushes are no longer needed in most situations |
| ECM Mechanika Slim PID | Heat exchanger, 1.9 L | Three preset temperatures: 248, 255 and 262 °F |
| ECM Mechanika Max | Heat exchanger, 1.9 L | Regulates by brew group temperature in 1-degree steps |
| ECM Technika V Profi PID | Heat exchanger | Temperature adjustment and shot timer; tank or in-line water |
| Rancilio Silvia Pro | Dual boiler, 0.3 L / 1.0 L | Dual PIDs, brew temperature variance under 1 °F |
| Profitec Pro 300 | Dual boiler | Gicar PID, holds within a degree of the set temperature |
| Profitec MOVE | Dual boiler | Dual PID in 1-degree steps |
| Profitec Pro 600 | Dual boiler, 0.75 L / 1 L | Dual PID, each boiler regulated independently |
| Profitec Drive | Dual boiler, 0.75 L / 2.0 L | Dual PID with programmable pre-infusion |
| ECM Synchronika II | Dual boiler, 0.75 L / 2 L | OLED PID with separate temperature for each boiler |
Other PID machines include the Profitec RIDE, Pro 700, ECM Mechanika VI Slim and the Synchronika editions. Not every machine lists one: the ECM Casa V and 969.Coffee Elba 3 listings do not mention a PID. New PID espresso machines in our range run from about $1,200 to $3,700 at the list prices on our site, which change over time. See them all in semi-automatic espresso machines.
Which PID espresso machine fits you?
- Mostly espresso, small budget or small counter: the Profitec GO, a compact single boiler with PID and shot timer.
- Espresso only, with an E61 group: the ECM Puristika, which has no steam wand at all.
- Single boiler with an E61 group and adjustable steam temperature: the ECM Classika PID.
- Milk drinks on a heat exchanger: the Profitec Pro 500 PID for fewer cooling flushes, or the ECM Mechanika Max for group-based regulation and a plumbable rotary pump.
- Direct brew temperature control while steaming: a dual boiler. The Rancilio Silvia Pro is the compact option; the Profitec Drive adds flow control and programmable pre-infusion.
- Lever brewing with PID: the Profitec Pro 800 Lever has a Gicar PID behind the drip tray.
Frequently asked questions
Do I need a PID on an espresso machine?
It is not required to make good espresso, but it makes brew temperature more stable and adjustable in degrees, which helps when you change roasts or dial in a new coffee.
What temperature should I set on a PID espresso machine?
La Marzocco sets its machines to 200 °F (93 °C) at the factory and suggests going higher for light roasts and lower for dark roasts. On a heat exchanger the PID sets the boiler, so use the manual’s chart to see which boiler setting gives your target brew temperature.
Does a PID heat exchanger still need a cooling flush?
Often a shorter one. ECM’s heat exchanger manual still calls for a short flush before brewing, while the Profitec Pro 500 PID listing says routine cooling flushes are no longer needed in most situations.
Can you add a PID to an espresso machine?
Enthusiasts have retrofitted PIDs since at least 2001, but that means working on mains-voltage wiring inside the machine. Leave it to a qualified technician, or buy a machine with a PID built in.
Sources
- La Marzocco Home: A brief history of the PID
- Wikipedia: Proportional-integral-derivative controller
- La Marzocco Home: The essential guide to mastering espresso at home
- La Marzocco Home: Basic espresso theory
- ECM: Mechanika VI Slim and Mechanika Slim PID user manual
- ECM: Classika PID user manual
- ECM: Our technology
- Rancilio Group: Silvia Pro X dual boiler with two PID controllers
For a focused example of choosing between two PID-equipped machines, read our Profitec MOVE vs GO guide. It compares drink preparation, controls and counter space, helping you decide which workflow suits you once temperature adjustment is already on your checklist.