Diagnosis
The primary cause of a consistently weak, watery espresso from your De'Longhi Magnifica S is insufficient resistance during extraction. This is almost always due to the coffee grounds being too coarse, preventing a proper "puck" from forming in the brew unit. Worn grinder burrs or a failing pump that cannot achieve 9 bars of pressure are secondary but common culprits.
How to Fix It
- Adjust the grind fineness. Locate the black dial at the bottom of the bean hopper. Turn it incrementally toward the "+" symbol to make the grind finer. After each adjustment, run a brewing cycle without a cup to purge old grounds, then test.
- Perform a thorough clean. Remove the brew unit by lifting the handle and pulling it out. Rinse it under warm water, carefully cleaning the metal filter, and let it air dry completely before reinserting.
- Check your dose setting. Ensure the machine's coffee quantity knob (or menu setting) is not set to the minimum. Increase the dose to deliver more ground coffee per shot.
If That Didn't Work
- Descale the machine. Severe limescale buildup in the thermoblock and internal lines can disrupt water temperature and flow, leading to under-extraction. Use only De'Longhi brand descaler or a citric acid solution as specified.
- Test the pump pressure. If adjustments and cleaning yield no improvement, the pump (part #5113211291) may be failing. A professional service check is needed to diagnose and replace it.
- Inspect the grinder burrs. If the machine is old or has processed many pounds of beans, the ceramic burrs may be worn and unable to produce a fine enough grind, requiring replacement.
Heads Up
Bean selection significantly impacts body. For a richer, stronger shot, use fresh, oily dark roast espresso beans. Light roasts or stale beans will inherently produce a thinner, more acidic coffee regardless of your machine's settings.