Learn what to do when the brew pressure drops to 0 and/or fluctuates while brewing on a machine with both a PID and vibration pump.
- If it drops for a few seconds, then builds back up:
It could be that the steam boiler is filling with water while you are brewing. If the boiler needs water, a solenoid valve will open and direct water to fill the boiler, causing the brew pressure to drop. When the boiler is filled the solenoid valve closes and the pressure builds on the coffee again. If this happens on a regular basis there may be a leak in the vacuum relief valve or from some other spot in the machine. Check out the video below for help resolving this issue:
Profitec Pro 500: How to Clean or Replace Vacuum Relief Valve
- If it cycles up and down during the brewing:
The pump is being affected by a voltage drop due to power being sent to the heating element. When you look at the PID display you will see a small dot that illuminates whenever the heating element is energized. If this pressure drop corresponds to the small dot being illuminated then you can be sure that is what's happening. You will also hear an audible change in the sounds of the pump when the pressure drops. The best thing you can do for this is to make sure that the machine is on a circuit without other appliances that are operating and drawing power.