Machine powers on but does not heat; both brew and steam boilers remain cold and temperature does not rise.

Safety first: Turn OFF and unplug the machine. Allow all components to cool. High voltages are present around heating elements and relays.

Steps to diagnose:

• Check high-limit thermostats: Locate the manual-reset safety thermostats on the boilers (small round devices with a reset button). Press the reset button firmly. If it clicks, it was tripped. Restore power and test heating.
• Inspect wiring to elements: Look for burned or loose wires at the heating elements and relays. Tighten or replace as needed.
• Test heating elements: With power disconnected, measure resistance across each heating element. An open circuit indicates a failed element that must be replaced.
• Check main heating relay/contactor: Verify that the relay energizes when the machine calls for heat. If the coil is powered but contacts do not close, replace the relay/contactor.
• If unsure or uncomfortable: Heating circuit work is high-risk. If you cannot confidently identify the fault, contact a La Marzocco service technician.