The #1 issue with your 100, 125, or 155 steamer is it WILL get dirty and that WILL cause issues in filling, pump problems, solenoid clogging, and poor steam volume. Although we have done videos on how and where to drain the boiler, as well as stating this in the owner’s manual when I ask a customer with issues as above….”when is the last time you drained it”? there is usually silence, then a question of how do you do that, or what do you mean by draining it?
The boiler needs to be emptied (COLD MACHINE ONLY) once every 10 days to 2 weeks for full-time users. Sediment will develop and circulate throughout the boiler and get into smaller passageways and clog stuff. This will shorten the life of the pump and the solenoid as it will get restricted like a clogged artery. As well, the water sensor will get dirty and won’t read the correct fill level
The drain plug is at the base of all the refill machines and covered by a black rubber flap. Open the flap, and the drain plug is exposed. On the 100 and 125 machines, the size of the tool needed is a 6mm Allen. On the 155 it’s a 19mm hex. Drain it until all the water is out and see what it looks like. If it’s milky or dirty and looks like dirty beach sand, then it needs to be done more frequently. If it’s clean and looks like you can drink it, then there should be no internal issues. Keep it clean, and it will perform well and have many fewer issues.