Takagi TK-110U-E 140,000 BTU Natural Gas/Liquid Propane Outdoor Non-Condensing Ultra-Low NOx Tankless Water Heater

Takagi TK-110U-E Outdoor Tankless Water Heater — 140,000 BTU | Natural Gas or Propane

The Takagi TK-110U-E is a 140,000 BTU outdoor tankless water heater built for residential use in warm climates — ideal for homes in the South, Southwest, and Pacific Coast regions where winter temperatures stay above 40°F. It delivers on-demand hot water at up to 6.6 GPM, enough to supply two showers running simultaneously at a typical 45°F temperature rise. It runs on natural gas and converts to liquid propane in the field with no additional parts.

Backed by one of the best warranties in its class — 15 years on the heat exchanger, 5 years on parts — the TK-110U-E is built for long-term reliability. Takagi customers regularly report units lasting 20+ years with routine maintenance.

Who is this the right fit for? This unit is best suited for 1–2 bathroom homes in warmer climates looking to replace a traditional tank water heater with an efficient, wall-mounted outdoor unit. It works with standard domestic hot water systems, recirculation systems, and combined domestic/heating applications. It is comparable to entry-level outdoor units from Rinnai and Noritz but is typically priced lower and includes a remote control as a standard feature rather than an add-on.

Key Features

• 140,000 BTU / 6.6 GPM max flow rate — sufficient for 1–2 bathrooms simultaneously in warm climates
• Outdoor-rated — no venting into the home required; mounts directly on an exterior wall
• Field-convertible — easily switches from natural gas to liquid propane on-site
• Copper heat exchanger — provides efficient, long-lasting heat transfer
• Ultra-Low NOx certified — emits less than 14 ng/J (<20ppm), meeting strict California and regional air quality standards
• Remote control included — adjust temperature without accessing the unit
• Built-in safety protections — freeze protection, overheat shutoff, surge protection, and self-diagnostic error codes
• Warranty: 15 years on heat exchanger, 5 years on parts (residential)

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Technical Specifications:

Dimensions & Venting: