What kind of water does the Lelit recommend?

By Di Pacci USA Coffee Specialists · Updated July 2, 2026

Short answer: Lelit recommends a water hardness of 35 to 85 ppm (total dissolved solids). That range keeps enough minerals in for good extraction and reliable machine operation, while staying low enough to prevent the scale buildup that damages boilers and valves. Below we explain why the range matters, what to avoid, and how to hit it at home.

Why Water Quality Matters for Your Espresso Machine

Most coffee enthusiasts focus on beans, grind size, and technique, but what you pour into the reservoir is the single largest factor in how your espresso tastes and how long your machine lasts. Espresso is roughly 90% water, so mineral content directly shapes flavor. Just as importantly, the wrong supply quietly damages the machine from the inside.

There are two failure modes at either end of the scale. A supply that is too hard leaves scale, a mineral crust that clogs boilers, valves, and heating elements and leads to costly repairs. One that is too soft or too aggressive can corrode internal components and produce flat, under-extracted coffee. The goal is a balanced middle.

Lelit's Recommended Water Hardness: 35 to 85 ppm

Lelit recommends keeping hardness within a total dissolved solids (TDS) range of 35 to 85 ppm. Staying inside this window does two things at once:

• Protects the machine — low enough mineral content that scale does not accumulate inside the boiler and group.
• Preserves flavor — enough calcium and magnesium to extract the desirable compounds that make espresso taste rich and balanced.

Below about 35 ppm, the supply is too soft: coffee tastes flat, and there is another problem covered in the next section. Above roughly 85 ppm, the risk of limescale climbs, and the machine will need descaling far more often.

Why You Should Avoid Pure RO and Distilled Water

It is tempting to assume that the purest possible supply is the safest for an expensive machine. With Lelit, the opposite is true. Reverse osmosis (RO) and distilled water have almost no mineral content, and Lelit machines rely on conductivity for the steam boiler's fill probes to detect the level. With near-zero minerals, the sensors cannot "see" the tank, so the machine may read empty even when it is full.

If you use RO or distilled as a base, it needs to be remineralized. Products with pre-measured mineral packets are formulated to bring purified water into the ideal espresso range, giving you precision and consistency.

How to Hit the Right Range at Home

Getting into Lelit's window is straightforward once you know your starting point:

• Test first. An inexpensive TDS meter or hardness test strip tells you where your tap supply sits. Retest every few months, since municipal hardness changes seasonally.
• Filter moderately hard supplies. A quality carbon filter reduces chlorine and impurities and moderates hardness. Good for readings only slightly above range.
• Blend or remineralize extremes. Mix filtered or distilled with tap to reach target hardness, or add mineral packets to purified water for lab-consistent results.
• Consider a filtration setup for plumbed machines. If your Lelit is plumbed in, a dedicated softening and filtration system keeps the supply safe without manual mixing.

Even with ideal input, periodic maintenance still matters. Testing what comes from your group head quarterly is the simplest way to catch problems before they reach the boiler.

Frequently Asked Questions

What water hardness does Lelit recommend?
Lelit recommends a total dissolved solids (TDS) hardness of 35 to 85 ppm. This range protects the machine from scale while retaining enough minerals for good extraction and reliable water-level sensing.

Can I use distilled or reverse osmosis water in a Lelit?
Not on their own. Pure distilled and RO water have almost no minerals, so the boiler's fill probes cannot detect the level and the machine may misread the tank as empty. If you use them, remineralize first with mineral packets to reach the 35 to 85 ppm range.

How do I know what my tap water measures?
Use an inexpensive TDS meter or hardness test strip, and retest every few months. Municipal hardness changes seasonally, and softening systems wear out over time.

Choosing and Supporting Your Lelit at Di Pacci USA

Good water protects a good machine. At Di Pacci USA, every purchase is backed by expert advice, flexible finance, and after-sales support from our team, so you can set up your Lelit correctly from day one and keep it performing for years.

Explore our range of Lelit home coffee machines or browse the full Lelit coffee machine collection. Full water and maintenance guidance for each model is published on Lelit's official website.