Boiler Pressure Switch

The espresso coffee machine pressure switch needs to be replaced if:

• The safety valve is venting due to the boiler overheating
• The group temperature is too hot ie over 95C
• Not getting enough steam from the wand.

A new pressure switch is factory preset so will not need to be adjusted - it will restore your correct boiler and group temperature. Most boilers are set at 126c which is approx 100c for water and 94c for group.

Q. How does a pressure switch on an espresso coffee machine work?

A. As the temperature builds up in the boiler, steam increases creating pressure inside the boiler. This extra pressure triggers the spring to rise, causing the contacts to open and power is removed from the element.

Q. Can you adjust the pressure switch on the coffee machine?

A. The pressure switch  is controlled by a screw on the top of the pressure switch. Turning the screw clockwise decreases the pressure, and turning it anticlockwise increases the pressure.

Q. At what pressure should I extract espresso coffee?

A.Nine bars of pressure, which is nine times the weight of air at sea level, is considered ideal for extracting espresso. 

Q. What happens if espresso pressure is too high?

When the pressure is too high, it can lead to over-extraction, which means that more of the coffee grounds are dissolved into the water. This can result in an overly bitter and unpleasant taste.