Brew Boiler Maintenance

Lucca A53 DP / Vivaldi II: Adjusting the Expansion Valve (OPV)

Follow these instructions to help you remedy an expansion valve that's dripping steadily into your Lucca A53 DP's drip tray.

Tools Needed:
- #3 Phillips screwdriver
- 21mm crescent wrench or adjustable wrench

NOTE: Before adjusting the expansion valve, verify that the line pressure going to the machine is within 30-45 PSI. We recommend using a pressure regulator on the water line going to the machine. Excess line pressure can damage your machine's internal components and void your warranty.

1. Remove the drip tray and unscrew the two fasteners on the lower front panel as shown here.

2. Identify the expansion valve.

3. Use the 21mm crescent wrench or adjustable wrench to turn the lower fitting on the expansion valve. Tightening this fitting increases the expansion valve's pressure threshold. 

4. Turn the expansion valve adjustment fitting until the valve stops leaking steadily. It is normal for this valve to release a few drops of water occasionally while the machine is at full temperature, but it should not be leaking steadily and it should not leak when the machine is off and cool.

NOTE: If no amount of tightening stops the steady leak from the expansion valve, it's likely that the seat gasket inside the valve has worn out and will need to be replaced. Servicing the expansion valve and replacing the seat gasket is a regular maintenance part of the machine's service life.