Steam & Steam Boiler Maintenance

LUCCA M58: Steam Fill Solenoid Inspection

Below are photos showing how to check and take apart a steam fill solenoid valve on a Quick Mill LUCCA M58 espresso machine. (Difficulty ☕☕☕)

If your machine has flow through the group head but the pump constantly runs, attempting to refill the steam boiler, then a likely suspect is a bad steam fill solenoid valve.

If your machine over-fills or fails to fill the steam boiler, a defective or dirty fill solenoid valve may be the cause.

Before attempting to check the solenoid valve you will want to unplug your machine from the wall and allow it to fully cool off. You will also need to remove the side panels.

Tools required:

  • 17mm deep socket & socket wrench
  • vice grip / adjustable wrench
LUCCA M58: Steam Fill Solenoid
LUCCA M58: Steam Fill Solenoid
LUCCA M58: Steam Fill Solenoid
LUCCA M58: Steam Fill Solenoid
LUCCA M58: Steam Fill Solenoid

"Check for flow through the hole by turning machine on and running pump. Be sure to cover the hole as it will spray water when the pump is ran. Also, be sure that the black solenoid coil wires aren’t exposed and touching any other parts"

If the solenoid valve body sprays water when the pump is running then the black solenoid box and the metallic solenoid shaft likely need to be replaced. You can test if water runs through it by lifting the brew lever with the solenoid off of the brass valve body.

If no water escapes from the bare valve body when the pump is run, then it's likely that the no-flow condition is caused by an obstruction further upstream. Refer to the following articles to continue troubleshooting:

LUCCA M58: Pump Outlet Gicleur Blockage
LUCCA M58 V2: Replacing Water Inlet