Machine will not start a coffee cycle, display shows E01 shortly after power-on.

Safety first: Switch the machine off with the main power button and unplug it before removing any parts. Allow hot components to cool.

Step-by-step:

• 1. Check water tank and seating: Remove the water tank, rinse it, and ensure the outlet valve at the bottom moves freely. Refill with fresh water and firmly reseat the tank so it fully engages the inlet port.
• 2. Bleed air from the system: Power the machine back on. If your Siemens model has a hot-water outlet, open the hot-water function and run water for 20–30 seconds to purge air. If E01 clears, test a coffee cycle.
• 3. Inspect inlet filter and softener: If a Siemens water filter cartridge is installed, remove it and try running the machine without it. A clogged filter can trigger E01. Replace the filter if flow improves without it.
• 4. Check for kinks or restrictions (plumbed-in models): For models connected to mains water, inspect the inlet hose at the rear for kinks or crushing. Ensure the shut-off valve is fully open and any external filter is not blocked.
• 5. Flowmeter check (advanced): If you are comfortable removing the top cover, locate the plastic flowmeter in the water line from the tank/inlet. Check for scale or debris in the inlet/outlet ports and gently flush with warm water. Do not pry on the internal turbine wheel.
• When to call a technician: If E01 persists after confirming water supply and cleaning, the flowmeter or control board may be defective and should be tested/replaced by a Siemens service technician.