Best 27 kW electric tankless water heaters

Top pick: EcoSmart ECO 27 — the one 27 kW model with a real track record and a wide dealer network, so parts and support are easy to find. Self-modulating, so it only draws what the hot water demand needs.

Who the others suit:

• Optimal Opti27 Plus — best for a long-term install: Wi-Fi control and a 25-year warranty, for someone who wants to set it and forget it.
• Optimal Opti 27 — same platform without the extras, if you don't need app control.
• Titan N270 — a familiar whole-house name with digital temperature control; check your panel can carry its 112 amps.
• APUS / ThermoMate 27 kW — budget-friendly picks for a single-bathroom or mild-climate install.
• PioneerWorks — only if you confirm the listing is the 27 kW version; the listing details are muddled.

All 27 kW units need roughly 112–120 amps at 240V, so have an electrician confirm your service size before buying.