How to Descale an Espresso Machine

How often you descale depends on two things: how hard your water is and whether a softening filter treats it first. With unfiltered water, we estimate every 5 to 6 months in soft water and every 4 to 6 weeks in very hard water. With a softening filter that you change on time, you may rarely need to descale at all. Test your water first, then use the estimated guide below. Your machine’s own prompt or manual always wins.

How often to descale: an estimated schedule by water hardness

Hardness is usually given in grains per gallon (gpg) or parts per million (ppm) as calcium carbonate. One grain per gallon is about 17.1 ppm. The intervals below are our estimates for unfiltered water at normal home use, not manufacturer figures. Use them only if your machine has no descale counter and your manual gives no interval.

Water hardness	gpg	ppm	Estimated descale interval (no filter)
Soft	0 to 3	0 to 50	Every 5 to 6 months
Moderately soft	3 to 7	50 to 120	Every 3 to 4 months
Moderately hard	7 to 10	120 to 170	Every 8 to 10 weeks
Hard	10 to 14	170 to 240	Every 6 to 8 weeks
Very hard	14 and up	240 and up	Every 4 to 6 weeks

Adjust the estimate for your use:

• Heavy use (8 or more drinks a day): move one row down.
• Softening filter, changed on schedule: descale when the machine asks. If your machine has no counter, check for scale about every 6 months (our estimate).
• Your machine has a descale counter: set the hardness in the menu correctly, then follow the prompt. A wrong setting makes the prompt come too late or too early.

How to test your water

1. Read your water report. US water utilities publish an annual Consumer Confidence Report. Look for “total hardness.” If it gives mg/L, that is the same as ppm.
2. Use a test strip. Dip a water hardness test strip in cold tap water and compare the color to the chart. Jura includes one in the box with its machines.

Test again if you move, change your water source, or add a softener.

What scale does to each machine type

Scale is calcium and magnesium carbonate that drops out of water when it heats. Where it collects depends on how the machine heats water.

• Superautomatics (Jura, De’Longhi, Philips, Miele) heat water in a thermoblock, a small block with a narrow water path. Scale narrows that path quickly. Flow slows, cups come out cooler, and the machine can stop with an error.
• Thermoblock and thermocoil semi-automatics (De’Longhi Dedica, Breville Bambino, Barista Express) have the same narrow path. They also have small valves and a steam path that scale can block.
• Single boiler machines (Gaggia Classic Evo Pro, Rancilio Silvia) collect scale on the heating element and in the solenoid valve. Loose flakes can jam the valve.
• Heat exchangers and dual boilers have larger boilers, more valves and sensors. Scale on a level probe or a heating element can stop the machine.
• Lever machines (La Pavoni) collect scale on the element and in the group. The first signs are slower heat-up and weaker steam.

Our guide to boilers and pressure explains each heating system.

Which descalers to use and which to avoid

Use a descaler sold for espresso machines and mix it exactly as the label says. Most are based on citric, lactic or sulfamic acid.

Product	Use it for	Notes
Your machine brand’s own descaler	Any machine with a descale program	The program’s soak times and volumes assume it
Urnex Dezcal powder	Boilers, thermoblocks, levers	The packet label mixes one 1 oz packet with 32 oz of water
Jura descaling tablets	Jura superautomatics	Dissolve fully before you start the program
White vinegar	Do not use	Acetic acid can attack seals and the smell is hard to rinse out
Lemon juice, household or dishwasher descalers	Do not use	Unknown strength, pulp, or not made for coffee machines

Vinegar does dissolve scale. The problem is the rest of the machine: acetic acid can harden seals and O-rings, and owners commonly report a sour taste after many rinses.

How to descale a superautomatic

Superautomatics run their own descale program. You prepare the machine and stay nearby. The example below follows Jura’s sequence; De’Longhi and Philips machines are similar.

1. Remove the water filter from the tank. Descaler damages the filter media.
2. Empty the drip tray and grounds container.
3. Start the descale program from the maintenance menu. On a Jura E8, it is under machine status.
4. Add the descaler when the display asks. Jura’s manuals tell you to dissolve the tablets fully in water first. Follow the volume your model’s manual gives.
5. Put a container under the coffee and milk spouts. Use one that holds the volume your manual gives.
6. Empty the tray and refill the tank with fresh water when prompted. The machine then rinses itself.
7. Do not switch off mid-cycle. If the power fails, run several hot water cycles before you make coffee.

Expect the cycle to take an estimated 30 to 45 minutes. This Jura descaling guide gives the menu path for each current model. If a cycle stops halfway, check that the tank has water and the drip tray is empty and fully seated, then follow the display.

How to descale a semi-automatic

Thermoblock machines with a descale mode are the easiest. On the Breville Barista Express, the manual says to descale when the Clean/Descale light is solid, not flashing. Dissolve the descaler in 1 liter of water in the tank. Then enter descale mode with the button combination in your manual. The machine runs solution through the group, then the steam and hot water paths. Do not remove or fully empty the tank during the cycle. Finish with a full tank of fresh water.

Single boiler machines without a program, like a Gaggia Classic Evo Pro, need a manual cycle:

1. Remove the water filter if one is fitted. Fill the tank with descaler mixed as the label says.
2. Switch on and let the machine heat.
3. Run about a cup of solution through the group, then a little through the steam wand.
4. Switch off and let the solution sit for the time the descaler label gives.
5. Repeat until the tank is nearly empty.
6. Rinse the tank. Run at least two full tanks of fresh water through the group and wand.

Dual boilers and heat exchangers need more care. The Breville Dual Boiler has its own program. Breville’s manual says to let the machine cool for at least an hour. You then drain each boiler through descale screws under silicone covers on the front. Breville allows about 1.5 hours for the whole job. For E61 heat exchanger machines, many dealers recommend treating your water so you never need a full boiler descale. If yours is already badly scaled, have a technician do it. Some retailers say water damage can void the warranty, so read yours before you start.

How to descale a lever machine

A direct lever like the La Pavoni Europiccola has a pressurized boiler with a removable cap. Never open the cap while the machine is hot or under pressure. Unplug it, let it cool, and open the steam knob to release any pressure first.

1. Fill the boiler to the top of the sight glass with descaler mixed as the label says.
2. Heat the machine, switch it off, and let the solution work for 20 to 30 minutes.
3. Raise the lever without coffee to run solution through the group. Open the steam wand too.
4. Stop when the boiler is about a quarter full. Switch off, cool, release pressure, and drain.
5. Fill with clean water and flush through the group and wand. Repeat until you taste no descaler.

The older US La Pavoni manuals say to descale 2 to 3 times a year for the Europiccola and 4 to 5 times a year for the Professional. Hard water needs more. This La Pavoni descaling guide covers the brass color change you may see after an acid clean. You can also read our Europiccola review for ownership details.

What a water filter changes

A softening filter removes much of the calcium and magnesium before water reaches the heater. Jura’s manuals go furthest. The J6 and J8 manuals, for example, say the machine no longer has to be descaled while you use a CLARIS Smart cartridge. Change it when the machine prompts. Jura still advises that you descale the water tank itself from time to time.

Two rules apply to every filter. First, tell the machine you use a filter, so the counter changes. Second, change the cartridge on time. A spent filter gives no protection. For Jura owners, the CLARIS Smart+ cartridge fits the current E, S, J and Z models. Our water filter guide covers other machines and the cost per year.

Do not switch to distilled water to avoid descaling. Many boiler machines use a level probe that needs some minerals to sense water.

Signs you waited too long

Descale now, then shorten your schedule, if you see any of these:

• Shots or drinks take noticeably longer to flow than they did a few weeks ago.
• Coffee comes out cooler than usual.
• The pump is louder, or it buzzes with little flow.
• A lever or boiler machine takes longer to heat, or the steam is weak.
• White flakes in the drip tray or the cup.
• An error code about heating or flow on a superautomatic.

If two descale cycles in a row do not restore flow, stop. A blocked valve or failed heater needs a repair, not more acid. Our troubleshooting guide helps you find the cause. Also descale on time to protect your warranty, since some brands exclude scale damage.

FAQ

Is descaling the same as cleaning? No. Descaling removes mineral scale from the water path. Cleaning removes coffee oil from the brew group and basket. You need both. Read our cleaning guide for that schedule.

Can I descale too often? Descaler is a mild acid. Very frequent use adds wear to seals over years. The risk of too little descaling is much greater, so follow the schedule above.

My coffee tastes odd after descaling. What now? Run more fresh water through every path, including the steam wand and hot water spout. If the taste stays, run the cleaning program too, since old coffee oil can also cause it.