Thermostats
Three thermostats
No probes and no level sensor. Rancilio's wiring diagram shows three thermostats at 100, 140 and 165 °C, and labels every one "safety thermostat". Reading them as brew, steam and safety cut-out comes from their ratings, not from Rancilio. Rancilio gives owners no method for this. Its manual says to unplug and let the machine cool before opening it, to use only original spare parts, and, for any problem it does not list, to contact its technical support. Treat it as technician work.
Seattle Coffee Gear's 2016 video says the two on top control the temperature and are not resettable; the safety one sits lower, with a red cap. Espresso Parts says the 165 °C one has an M4 stud into the front of the boiler that can snap if over-tightened, so turn it only slightly past hand-tight, and use thermal paste on the other two.
Reset the safety thermostat
Rancilio's 2019 manual and its current US manual give this on a page headed "This operation should only be conducted by a qualified technician". The 2024 EU manual drops the page altogether. The 2024 EU manual says only "Call technical support" when the machine does not heat. These are the steps on the technician's page, with Clive Coffee's note.
- Unplug the machine and wait until it has cooled completely.
- Remove the screws on top and lift off the cup tray.
- Push in the red button. Clive: if it clicks down, it had tripped.
- Refit the cup tray.
- Plug in, switch on, and prime again as in first start-up.
- Check that it works. When in doubt, the manual says, contact customer service.