A03
DeLonghi Coffee Machine
Severity:What Does This Error Mean?
A03 means the machine has detected enough scale buildup to require a descale cycle. Use DeLonghi descaler and the built-in descale programme. The process takes around 30 minutes.
Affected Models
- DeLonghi Magnifica
- DeLonghi Magnifica Evo
- DeLonghi PrimaDonna
- DeLonghi Eletta
- DeLonghi Dinamica
- DeLonghi Maestosa
Common Causes
- Scale buildup from hard water in the boiler and water circuit
- Mineral deposits reducing heating performance
- Normal wear-based trigger from the machine's internal scale counter
How to Fix It
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Purchase DeLonghi descaler.
Use DeLonghi EcoDecalk liquid descaler or DeLonghi-approved descaler tablets. Avoid generic descalers that may contain harsh acids not compatible with DeLonghi components.
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Prepare the machine.
Empty the drip tray and water tank. Place a large container (at least 2 litres) under the steam and coffee spouts. Fill the tank to the descaling marker with the descaler and water mix as directed on the product.
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Start the descale programme.
On most DeLonghi models, press and hold the descale button or navigate to Maintenance > Descale. Follow the on-screen or LED prompts. The programme runs in phases and takes approximately 25–30 minutes.
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Complete the rinse phase.
When prompted, refill the tank with fresh water for the rinse phase. Do not interrupt the programme. The A03 indicator resets automatically when the descale cycle finishes.
When to Call a Professional
Descaling is a routine maintenance task. If A03 returns within a week of completing a full descale, contact DeLonghi support — there may be an issue with the scale counter or internal circuit.