Are the Opti 27 and Opti27 Plus the same heater?

Yes. Both are 27kW, 4.5 GPM, 208/220/240V wall-mounted units with the same dimensions, 1°F accuracy, Wi-Fi app control, and 25-year residential warranty. The Plus name adds no hardware difference in the listed specs.

Which is better for a whole home?

Either one, if your electrical service supports it. A 27kW unit draws up to 112 amps and needs three 40-amp double-pole breakers with 3 x 8 AWG wire. In cold climates, 4.5 GPM covers roughly one shower plus a sink, not two showers at once.

Is the Opti27 Plus worth the extra $11?

Only for availability. It is $740.00 at Home Depot as of November 7, 2026 versus $729.00 for the Opti 27, and five stores carry it versus three. If the Opti 27 is in stock, save the $11.

The warranty is identical: 25 years residential and 5 years commercial on both. Tankless electric heaters typically last 20 years or more, but scale buildup matters, so plan on descaling in hard-water areas.

Do both work with the same app?

Yes. Both list Wi-Fi and app control, and the Plus names iOS and Android support. You can track usage, set temperature, and get notifications from either.

What electrical panel do I need?

A 200-amp service is usually the practical minimum for a 27kW unit, and many homes need a panel upgrade first. Confirm with an electrician before buying either model.

Optimal Opti 27 Tankless Water Heater vs Opti27 Plus 27kW Electric Tankless Water Heater

These are the same heater. Both are Optimal 27kW, 4.5 GPM, 208/220/240V units with identical dimensions, 1°F temperature accuracy, ultrasonic flow sensing, Wi-Fi app control, and the same 25-year residential / 5-year commercial warranty. The only real difference is price and store count: the Opti 27 is $729.00 at Home Depot as of November 7, 2026, and the Opti27 Plus is $740.00 at Home Depot as of November 7, 2026. Buy the cheaper one unless the Plus is in stock when you need it.

Today the Optimal Opti 27 Tankless Water Heater costs $11.00 less at its best price.

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