How to Descale a Plumbed-In Espresso Machine (Step-by-Step Guide)

If your plumbed-in espresso machine is brewing slower, tasting off, or making strange noises, limescale buildup could be the culprit. Hard water leaves mineral deposits inside your machine’s internal components—especially in boilers and heat exchangers—and over time, this buildup reduces efficiency and can even cause permanent damage. Knowing how to descale a plumbed-in espresso machine is essential for any coffee lover or café owner who wants to protect their investment and enjoy barista-quality espresso every day.

Don’t worry—this guide walks you through the entire process, safely and step by step, even if you’ve never descaled before.

Why Descaling Your Plumbed-In Espresso Machine Matters

Plumbed-in espresso machines are directly connected to your building’s water supply, which means they’re constantly exposed to minerals like calcium and magnesium—especially in areas with hard water (water with >7 grains per gallon or 120+ ppm hardness).

According to the U.S. Geological Survey, over 85% of American homes have hard water—making descaling not just helpful, but necessary.

Ignoring descaling can lead to:

• Reduced water flow and pressure
• Inconsistent brew temperature
• Increased energy consumption
• Premature machine failure

A study by La Marzocco found that espresso machines not descaled every 3–6 months (depending on usage and water hardness) were 3x more likely to require repairs within 2 years.

How Often Should You Descale a Plumbed-In Machine?

Unlike portable espresso machines, plumbed-in models run continuously and process more water—meaning scale builds faster.

Your ideal descaling frequency depends on:

💡 Pro Tip: Install an in-line water filtration system (like Everpure or BWT) to reduce scale and extend descaling intervals by up to 50%.

Tools & Supplies You’ll Need

Before you start, gather these essentials:

• Descaling solution (brand-specific or universal like Urnex Dezcal or Durgol Swiss)
• 2–3 liters of fresh, cool water (22–28°C / 72–82°F)
• Large container or bucket (to catch runoff from the drain line)
• Clean towels or rags
• Gloves (to protect hands from acidic solutions)
• Machine manual (for model-specific instructions)

⚠️ Never use vinegar. Despite popular belief, vinegar is too weak to fully dissolve limescale in commercial-grade boilers and can leave residues that affect taste. Stick to food-safe, citric- or lactic-acid-based descalers approved by your manufacturer.

For more on water chemistry and scaling, see the Wikipedia entry on water hardness .

Step-by-Step: How to Descale a Plumbed-In Espresso Machine

🔧 Important: Always turn off and unplug your machine before starting. Allow it to cool completely if recently used.

Step 1: Prepare the Machine

• Turn off the water supply valve (usually located under the counter).
• Open the hot water wand and steam wand to release pressure.
• Place a large container under the group head and drip tray to catch liquid.

Step 2: Mix the Descaling Solution

• Follow the product instructions. Typical ratio: 1 packet (28g) of Dezcal per 1 liter (34 oz) of water.
• Use room-temperature water—never hot, as it can cause premature reaction.

Step 3: Bypass the Water Line (If Required)

Plumbed-in machines don’t have a removable water tank, so you’ll need to temporarily disconnect the inlet line and place it into your descaling solution container.

• Some machines (e.g., Nuova Simonelli, ECM) have a “service mode” that allows internal circulation without plumbing disconnection—check your manual.

Step 4: Run the Descaling Cycle

1. Power on the machine.
2. Activate the brew group or use the machine’s auto-descale program (if available).
3. Run solution through until the reservoir is empty (~1–2 liters).
4. Let it sit for 10–20 minutes (as directed)—this allows the acid to dissolve scale.
5. Flush the system by running 2–3 liters of clean water through all circuits (brew, steam, hot water).

Step 5: Reconnect & Test

• Reattach the water inlet line.
• Turn the water supply back on.
• Run 1–2 blank shots of espresso and purge the steam wand to ensure no residue remains.
• Check for leaks and normal operation.

✅ Done right, your machine should now heat faster, brew more consistently, and last years longer.

Common Mistakes to Avoid

FAQ Section

Q: Can I descale my plumbed-in espresso machine without disconnecting the water line?
A: Yes—if your machine has a built-in descaling mode (common in Breville, Rocket, and La Marzocco models). This mode bypasses the main water line and circulates solution internally. Consult your manual or contact the manufacturer.

Q: How do I know if my machine needs descaling?
A: Watch for: longer heat-up times, weak steam pressure, bitter or metallic-tasting espresso, or error codes like “DESC” or “CALC.” Some machines display usage-based alerts.

Q: Is descaling the same as cleaning?
A: No. Cleaning removes coffee oils from the group head and portafilter (done weekly). Descaling removes mineral deposits from internal water paths (done every 1–6 months). Both are essential.

Q: Can I use tap water after descaling?
A: Yes, but for best results, pair descaling with a quality water filter. Filtered water reduces future scale and improves flavor. The Specialty Coffee Association recommends water with 50–100 ppm hardness.

Q: What if my machine won’t start the descale cycle?
A: Ensure you’re in service/descaling mode (often activated via a button combo). If unsure, refer to your manual or find a video tutorial for your exact model on YouTube (e.g., “Rocket R58 descale tutorial”).

Conclusion

Now that you know how to descale a plumbed-in espresso machine, you’re equipped to keep your coffee tasting perfect and your machine running smoothly for years. Regular descaling isn’t just maintenance—it’s an investment in flavor, reliability, and cost savings.

👉 Share this guide with fellow coffee lovers on Instagram, Pinterest, or your local barista group! And if you’ve just descaled your machine, tag us—we’d love to hear how it went.

Your espresso deserves the best. And so do you. ☕✨