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Takagi Line Hub

Takagi T T Commercial Water Heater — Specs, Features & Reviews

The T-T commercial line — single units or cascade up to 6 units for light-to-medium commercial DHW.

Updated May 2026 · Takagi Water Heaters

The T-T commercial line is Takagi's commercial-grade tankless. Single units cover small commercial; cascade configurations up to 6 units cover medium commercial.

T-T lineup

  • T-T1-OS-NG — outdoor commercial, 199k BTU, weather-sealed
  • T-T2-IN-NG — indoor commercial condensing, cascade-capable up to 6 units

Cascade capability — up to 6 units

Takagi T-T cascade supports up to 6 units in series — smaller ceiling than Noritz NCC (12 units) but adequate for:

  • Small restaurants (under 50 seats)
  • Salons and spas
  • Small hotels (under 30 rooms)
  • Light commercial / multi-tenant retail

For larger commercial applications, Noritz NCC cascade (12 units) is the better choice.

Warranty

10 years heat exchanger / 5 years parts / 1 year labor. Commercial use limits to 5 years heat exchanger.

Pricing

  • T-T1-OS-NG: $1,899-2,199
  • T-T2-IN-NG: $1,999-2,299
  • Cascade controller: $1,200-2,500

Install

Use Takagi/AO Smith-trained commercial installer. Cascade installs aren't appropriate for generic plumbers.

Bottom line

Right for small-to-medium commercial DHW. For larger commercial (hotels with 50+ rooms, large restaurants), Noritz NCC cascade is the better-supported choice.