When you order a new espresso machine, you may have to adjust the expansion valve periodically or before its first use. This component of the machine plays a critical role in pressure regulation to the group head, but the valve must be loosened before shipment and may require an adjustment. All espresso machines have this part for safety. Whether you’re considering La Marzocco, Sanremo, Nuova Simonelli, or another brand, be sure to familiarize yourself with the manual before pulling your first shot. Interested in learning more about the unique job of the expansion valve? We share the details below:
Why the Expansion Valve Is So Important
This small piece of equipment ensures that the pressure within the coffee boiler remains at 12-bar and never exceeds this measurement. Since the process of heating the coffee boiler causes water to expand, this expansion could potentially cause a rupture in the boiler if not regulated.
How to Adjust the Expansion Valve
The expansion valve is typically located in the drain box, so this part must be removed to access the valve. Here, we’ll reference the instructions included with the La Marzocco GS3. If you want to check the expansion valve before its first use or you’ve noticed that the pressure of the coffee boiler is not at the appropriate level, you can carefully turn the expansion valve with a small crescent wrench to the correct setting. If the pressure is too low, rotate the valve clockwise to increase pressure. To decrease the pressure, turn the valve counter-clockwise. If you’re performing the adjustment after the machine has been warmed up, be sure to use proper protective equipment. The expansion valve is capable of discharging water at temperatures up to 200 degrees Fahrenheit, so handling with caution is always recommended.
All commercial espresso machines are equipped with an expansion valve, and adjustments are sometimes necessary. If you’re ever in doubt on how to safely adjust this part, consult the manual of your machine or reach out to a certified espresso technician. Ready to take the next step in purchasing a high-quality machine? We carry a plethora of high-end espresso machines, and we’d love to help you find the perfect fit. If you have any questions about our products, just contact us for a consultation.