The short answer: buy a Dedica-specific 50.5mm shower screen—not a 51mm puck screen.
The De’Longhi Dedica EC685 uses a 51mm basket system, but the shower screen that sits inside its brew group is a different part. For a replacement, look for a screen explicitly named for the Dedica EC680/EC685 family, with a 50.5mm outside diameter and an M5 centre-screw fit.
The 51mm number is for your basket. It is not the shower-screen size.
This is the easy mistake to make with the Dedica. The filter basket and the shower screen sit close together, but they are not interchangeable accessories. A puck screen rests on top of coffee in the basket. A shower screen mounts inside the brew group, above the basket, and needs the correct screw location and outer profile to seat properly.
The dimensions shown are the published reference for the IMS DL200IM replacement, made for Dedica brew groups with an M5 centre screw.[1]
Use this four-point screen check
Your model is named
Look for EC685 in the compatibility list. A suitable replacement may also name EC680, EC785 or EC885, but the listing must identify the Dedica family—not just “51mm espresso.”
The outside diameter is 50.5mm
That is the relevant screen diameter for the specific Dedica replacement reference. Do not select a product only because it says 51mm.
The centre hole accepts the Dedica’s M5 screw
The replacement screen needs to align cleanly with the original centre screw. Reuse the original screw only when it is clean, undamaged and seats correctly.
The profile is made for the brew group
A flat loose mesh disc, a 58mm commercial screen or a basket puck screen is not a substitute for a properly shaped Dedica shower screen.
Important: A 51mm puck screen can complement your coffee routine, but it does not replace the brew-group shower screen.
Shower screen, puck screen, or filter basket?
Each part has a different job. Keeping the language clear helps you buy the right item and makes maintenance less confusing.
Shower screen
This is the fixed screen above the basket. It spreads water as it enters the coffee bed and is held in the Dedica group by a centre screw. Replace it only with a screen designed for your machine’s brew group.
51mm puck screen
This reusable disc sits on the tamped coffee before brewing. It can help keep the underside of the group cleaner and is sized to the Dedica’s 51mm basket—not to the shower-screen recess.
51mm filter basket
This is the basket inside the portafilter. Its 51mm designation guides purchases such as baskets, tampers and puck screens. It is not a measurement to use when choosing a brew-group screen.
Keep the screen clean before you assume it needs replacing.
Coffee oils and fine particles build up where you cannot easily see them. A clean screen supports consistent water flow; however, it will not correct stale beans, an unsuitable grind or a poorly prepared puck. Use this as a simple maintenance rhythm—not a promise of a specific taste result.
How to change a Dedica shower screen carefully
Work only when the machine is cool, unplugged and depressurised. If the screw is seized, stripped or the screen does not sit flat, stop rather than forcing it—damage to the group head is not worth a rushed replacement.
Cool, unplug and prepare
Let the machine cool completely. Remove the portafilter and place a towel under the group head to catch the original screen and screw.
Loosen the centre screw gently
Use a screwdriver that fits the screw head well. Keep the tool straight and apply controlled pressure so you do not slip or strip the screw.
Do not force a seized screw. Seek a qualified repair service if it will not release cleanly.
Clean the contact area
Remove old coffee residue from the brew-group surface with a soft cloth or suitable brush. Avoid sharp tools around the seal and inner surfaces.
Seat the new screen, then hand-tighten
Align the screen and centre hole, reinstall the original screw and tighten only until secure. An overtightened screen can deform, which defeats the purpose of fitting it carefully.[1]
Run water and inspect
Plug the machine back in, run a brief water-only flush and confirm the screen sits flat and the flow looks even. If it leaks, rattles or looks distorted, stop and recheck fitment.
Add a puck screen only after the brew group is sorted.
A proper shower screen keeps the machine’s brew group in order. A 51mm puck screen is a separate accessory for the coffee bed: place it on the tamped puck before brewing. It can be a useful companion for keeping the group cleaner, but it is not a repair part and cannot fix a worn or blocked shower screen.
Lastaforest fitment note: the MHW-3BOMBER Espresso Puck Screen is available in a 51mm option for the Dedica basket system. Confirm the 51mm variant at checkout.
Shop the 51mm Puck ScreenQuestions Dedica owners ask before replacing the screen
What size shower screen fits a De’Longhi Dedica EC685?
Can I use a 51mm puck screen as the Dedica shower screen?
Will a precision shower screen make every Dedica shot better?
How tight should the centre screw be?
What 51mm accessories can I use with a Dedica EC685?
Sources & fitment note: Shower-screen dimensions and Dedica EC685 compatibility in this guide refer to the published IMS DL200IM replacement-screen specification: 50.5mm outer diameter, 49.5mm inner diameter, 9mm height and an M5-compatible centre screw.[1] IMS confirms that Dedica EC680/EC685 machines use a 51mm group-head accessory system and that its DL series includes dedicated shower screens.[2] The MHW-3BOMBER product link is a 51mm basket-side puck-screen recommendation, not a shower-screen replacement. Verify live product fitment and your machine revision before purchase or installation.