Rocket Espresso Rocket R Nine One

MakerRocket Espresso
BoilerDual boiler
Brew boiler1.9 L
Steam boiler3.6 L
Water tankNot listed
Plumb-inYes, or reservoir
Voltage (US)Not listed
Maker's water filterNot listed

What water does this machine require?

Rocket Espresso hasn't published a limit our check can use for this machine yet, so the check can't give it a result. Whatever the maker does say is quoted below.

Will my water work with this machine?

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The maker's water guidance

What the maker says this machine needs from its water. This is machine care, not drinking-water advice.

From Rocket Espresso's guidance for this model.

  • Water type

    “The machine must be operated with soft, clean drinking water. If the local water supply has a high mineral content use a water softener.”

    Rocket Espresso R NINE ONE user manual (PDF created 2018-09-05, 28 pp.; Rocket document hosted by Seattle Coffee Gear), Safety instructions, item 15. Source (opens in a new tab), saved October 28, 2026.

  • Very pure water

    “Conversely very ‘pure’ waters may interfere with the electronic signals read by the machine for both boiler level and water reservoir level indications. Use a filtered water.”

    Rocket Espresso R NINE ONE user manual (PDF created 2018-09-05, 28 pp.; Rocket document hosted by Seattle Coffee Gear), Safety instructions, item 15. Source (opens in a new tab), saved October 28, 2026.

  • Very pure water

    “Use fresh, filtered water to fill the reservoir. Do not use distilled water.”

    Rocket Espresso R NINE ONE user manual (PDF created 2018-09-05, 28 pp.; Rocket document hosted by Seattle Coffee Gear), Maintenance, water reservoir. Source (opens in a new tab), saved October 28, 2026.

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Specs read from the maker's or seller's page.