Descale

When, and with what

The manual: "When the orange key light flashes, run a descaling cycle." How often depends on the water hardness setting; no fixed interval is given.

• Descaler: "Use De'Longhi descaler only. Using unsuitable descaler and/or performing descaling incorrectly may result in faults not covered by the manufacturer's guarantee." De'Longhi sells it as DLSC500 (Decalk Care; EcoDecalk on older packs): 100 ml per descale, says its product page.
• The 2016 and US manuals add that limescale damage is not covered unless you descale regularly. The Get Started guide forbids sulphamic or acetic (vinegar) descalers.
• Container: 1 litre (2026 manual); the US Get Started guide says at least 50 oz (about 1.5 litres).
• Time: about 25 minutes, with two rinses.

Start the cycle

The 2026 manual's steps.

1. Take off the filter holder, and take the softener filter out of the tank if one is fitted.
2. Pour 100 ml of De'Longhi descaler into the tank and top up with water to MAX.
3. Put a 1 litre container under the frother and the coffee spouts.
4. Hold the steam button for 10 seconds until the 3 buttons flash in sequence.
5. Turn the steam dial open, then press the steam button to start. The solution comes out of the frother in rinses and pauses.
6. Close the dial now and then to send a little through the coffee spouts, until the tank is empty.

Rinse twice

The 2026 manual's rinse.

1. When delivery stops (the orange light keeps flashing: the cycle is still running), empty the container and put it back.
2. Rinse the tank, fill it with fresh water to MAX and refit it.
3. With the dial open, press the steam button to start the rinse. Close the dial now and then to rinse the coffee spouts.
4. Repeat steps 1 to 3 for a second rinse, with the softener filter back in if you use one.
5. When the tank is empty, the orange light goes off and the 1-cup and 2-cup lights flash.
6. Close the dial to ○ and refill the tank with fresh water.

De'Longhi Dedica EC685: every job