Setup
Plumbing In vs Reservoir: Espresso Machine Water Supply Options
Most home espresso machines use a removable reservoir, but some prosumer and commercial-style machines can be plumbed directly into a water line — the choice matters more for kitchen layout than for shot quality.
Reservoir-fed machines
A removable tank is refilled manually and is the format used by every machine reviewed on this site — no installation required, works anywhere with access to drinking water, and can be moved or relocated on a countertop with no plumbing consequence.
Plumbed-in machines
A plumbed machine connects to a water line (often via a dedicated filter) and never needs manual refilling, at the cost of an installation step, a fixed location, and typically a model specifically designed or configured to support it — not every machine that has a reservoir can simply be plumbed in as an alternative.
Which to choose
For nearly all home buyers, a reservoir is simpler and more flexible, and it is what every machine covered on this site uses. Plumbing in makes sense mainly for a fixed kitchen installation, high daily volume, or a household where topping off a tank would be a genuine daily inconvenience rather than an occasional one.
What changes if you later want to plumb in
If you outgrow a reservoir-fed machine specifically because of refill frequency, that is usually a sign to look at machines and commercial-adjacent setups explicitly designed for a direct water line rather than trying to retrofit a reservoir-only consumer machine, which most manufacturers do not support.