ThermoMate 27kW Electric Tankless Water Heater vs GE 27kW Tankless Electric Water Heater

Both are 27kW, 240V, three-phase tankless heaters with self-modulating power and digital temperature control, so they perform alike on paper. The ThermoMate is the clearer pick for most buyers: it lists Wi-Fi, a cast aluminum heating block with three elements, 1°F temperature accuracy, 6.6 GPM, and ETL, CSA and UL listings, and owners report stable temperature through back-to-back showers. The GE is a solid whole-home alternative with overheat protection and ADA compliance, but its published details are thinner and it lacks the smart features and third-party listings the ThermoMate spells out.

• Choose the ThermoMate if you want Wi-Fi control, tighter temperature accuracy, and a unit with ETL, CSA and UL listings plus a cast aluminum heating block.
• Choose the GE if you prefer a brand-name whole-home unit with overheat protection and ADA compliance and do not need app control.