La Marzocco GB5 S AV 2/3 Group Dual Boiler Espresso Machine

The GB5 S is an updated version of the original GB5, released in 2005. We are pleased to reintroduce this machine with a fresh appearance and incorporating the latest advancements from La Marzocco. It is the final creation developed with guidance from our esteemed honorary president Piero Bambi, boasting elegant lines that pay homage to the original design.

The GB5 S - 2 group Dual Boiler Espresso Machine offers the options of EE, AV, and AV with scales. It also includes

• vacuum-insulated double-walled steam wands
• Luminaire electronics (like on the PB and KB90)
• piero caps
• dimmable barista lights

among other advanced features. Additionally, the machine boasts an easy-to-rebuild steam valve, similar to the one debuted on the KB90, and partially exposed groups to streamline barista workflow.

The aesthetic qualities of the La Marzocco GB5 S reflect the brand's dedication to design and purpose. From the understated side shields to the elegant Florentine lilies and the subtle insignia of il Marzocco on the cup rail, every detail is thoughtfully crafted to create a machine that exudes a sense of longevity.

GB5 S AV vs. GB5 X: Precision, Flexibility, and Independent Group Control

The La Marzocco GB5 series is dedicated to those who appreciate classical European aesthetics paired with the highest level of modern espresso performance. Both the GB5 S and the GB5 X are second-generation models (with the AV denoting Auto-Volumetric dosing as standard), ensuring shot-to-shot consistency in busy UK café settings.

(Image: London Coffee Festival 2025 - Prime Coffee Suppliers CE)

However, the GB5 X offers a significant step up in internal thermal engineering and control compared to the GB5 S, making it the choice for the most technically demanding coffee programmes.

The Critical Distinction: Boiler Configuration

The most important difference between the GB5 S and the GB5 X lies in how the water for the espresso shot is heated and controlled. This directly impacts your ability to switch between different coffee temperatures.

Technology and Performance: A Deeper Dive

Both machines are engineered for superior temperature stability, but the GB5 X is built for the absolute highest degree of precision and flexibility.

GB5 S: The Flagship Dual Boiler

The GB5 S carries forward the reliable architecture of the previous GB5, delivering exceptional stability through a powerful dual boiler system.

• Dual Boiler System: This uses separate boilers for the steam and for the brew water. However, the brew boiler is shared by all group heads.

  • This provides fantastic, stable temperature control (via Dual PID) but means all group heads must operate at the same brewing temperature.

• Aesthetics: The machine features red accents and a beautifully curved, stainless steel body, maintaining the elegant Florentine heritage.

• Key Shared Features (with the X):

  • Piero Group Caps: Re-engineered water path and flow meter positioning for high volumetric accuracy.

  • Water Sensor: An innovative sensor that measures the conductivity and hardness of the incoming water, enabling baristas to monitor filtration effectiveness and protect the machine from scale.

GB5 X: The Independent Multi-Boiler System

The GB5 X elevates the GB5 architecture by adopting a Multi-Boiler system, sharing the same hydraulic principles as La Marzocco's top-tier Strada model.

• Independent Saturated Boilers (Multi-Boiler): Each group head has its own dedicated, small coffee boiler. This is the key technical difference.

  • This allows the barista to program a different, precise brewing temperature for each group head. For example, Group 1 can be set to 93°C for a light-roasted single origin, while Group 2 is set to 91°C for a traditional espresso blend.

• Dynamic Pre-Heater: This additional layer of thermal stability ensures the water entering the independent boilers is already at an extremely stable temperature, reducing the heating load and enhancing consistency even during peak service hours.

• Hot Water Economiser: Standard feature, allowing the flow and temperature of the water from the hot water tap to be precisely adjusted, ideal for high-quality tea service or Americanos.

• Aesthetics: The machine is identifiable by its premium white accents on the lilies and logos.

Key Considerations for Purchasers

1. Deciding on Thermal Control: Why Choose One Over the Other?

• GB5 S Cost Efficiency & Simplicity: The GB5 S delivers exceptional thermal stability at a lower initial cost. It is the ideal choice if your café primarily runs one consistent espresso blend and you do not require different brewing temperatures simultaneously. Its shared coffee boiler system is highly reliable and simpler internally.
• GB5 X Temperature Flexibility & Precision: You should choose the GB5 X if your café frequently changes its menu to include single-origin coffees or light roasts that require different optimal extraction temperatures at the same time. The independent group boilers and Dynamic Pre-Heater offer the highest degree of fine-tuning and thermal stability available.

2. What about the AV (Auto-Volumetric) feature?

• Both the GB5 S AV and the GB5 X AV are high-precision volumetric machines. The barista starts the shot, and the machine stops it based on the pre-programmed volume of water.

• Crucially, both models are also available in the ABR (Auto Brew Ratio) configuration, which adds patented scales into the drip tray to stop the shot based on the weight (mass) of the espresso output, offering the ultimate consistency.

3. What are the shared electronic advantages?

Both machines benefit from La Marzocco's next-generation electronics:

• Digital Display: Intuitive interface for programming doses, auto-cleaning, and monitoring vital machine functions.

• Water Sensor: A highly valuable feature that helps monitor the performance of your water filtration system in real time, preventing costly scale damage.

• Eco Mode: A programmable standby mode that reduces boiler temperatures during quiet periods to improve energy efficiency.

About La Marzocco

La Marzocco has always focused on the values of integrity, impact, curiosity, courage and celebration. This is what has allowed them to continually innovate and persevere in the manufacturing of the finest in class specialty coffee equipment.