Lucca M58: Test the Fill Probe

Use these instructions to troubleshoot a constantly running pump, a pump that doesn't run, or a PID that fails to initialize.

Tools Needed:
- Phillips head screwdriver
- 12mm deep socket and ratcheting wrench
- Ratcheting wrench extension (optional)

NOTE: The machine should be off and cool to the touch when you begin. Open the machine's hot water valve and direct the wand into a large pitcher. Make sure the water reservoir is installed and full. If the machine is plumbed-in, make sure that the supply line is on and water is getting to the machine.

1. To start, remove the panels from the machine.

2. Identify the steam boiler fill probe.

3. Remove the electrical connection from the fill probe.

4. Power the machine on:

If the pump begins running immediately on start up, plug the electrical connector back onto the fill probe and wait a moment. If the pump stops running  when the fill probe wire is reattached, then the machine is working normally.

If the pump does not begin running with the fill probe wire unplugged... 
If the pump does not stop running when the fill probe wire is plugged back in, continue troubleshooting.

5. Use the 12mm socket to unscrew the fill probe from the boiler.

6. Re-connect the electrical lead to the fill probe and hold the fill probe against the boiler.

7. While continuing to hold the fill probe against the boiler, power the machine on. 

If the pump continues to run, the fill probe may need to be cleaned or the fill probe circuit may be faulty.

If the pump stops running, then the fill probe is working normally and the constant running condition is either caused by a stuck fill solenoid or a faulty pump circuit.

If the PID still fails to initialize, then either the CPU is failing to send power to the PID or the PID itself if faulty.