Power button alternates between red and green and the machine does not start brewing.

Safety: Use only Dolce Gusto–approved descaling solution or a compatible food-safe descaler. Never use vinegar in Dolce Gusto machines as it can damage seals and aluminum parts.

Descaling procedure (generic Dolce Gusto):

• Prepare solution: Fill the water tank with fresh water and add the recommended amount of descaling solution according to the product instructions.
• Insert no capsule: Remove any capsule and close the locking handle.
• Place a large container: Put a container (at least 1 liter) under the coffee outlet.
• Start descaling mode: On many models, turn the machine off, then press and hold the power button for about 5 seconds until it starts flashing green/orange or green/red (consult your specific model manual).
• Run hot cycle: Move the lever to hot and let about half the tank run through. Then center the lever and wait 2–3 minutes to let the solution act inside the thermoblock.
• Run cold cycle: Move the lever to cold and run the remaining solution through.
• Rinse: Empty and rinse the tank, fill with fresh water, and run at least one full tank (half hot, half cold) to flush out descaler.

If, after a full descale, the red/green flashing persists, the flow meter or thermoblock may be partially blocked or faulty and should be checked by a technician.