Rinnai RE140iN Tankless Natural Gas Water Heater - Compact, Reliable

Our review of the Rinnai RE140iN finds a compact, high-flow non-condensing tankless heater best suited to households that need steady hot water for multiple fixtures without sacrificing space. The RE140iN delivers up to 5.3 GPM and a robust 140,000 BTU rating while occupying roughly the size of a small suitcase, so the single biggest reason to consider it is its combination of reliable on-demand performance and a space-saving footprint for indoor installation.

Key Features

• Compact footprint: The small, suitcase-size enclosure makes it easy to install in cramped utility rooms where a tank would not fit.
• High flow capacity: Rated for up to 5.3 GPM, it can supply hot water to multiple fixtures simultaneously in many homes.
• Durable construction: Backed by a 15-, 5-, and 1-year residential guarantee for heat exchanger, labor, and parts, which supports long-term ownership confidence.
• Serviceability: Redesigned internal layout and sliding bracket simplify alignment and speed up professional installation and maintenance.
• LED display and diagnostics: The front LED lets you view error codes and reminders, making troubleshooting clearer for technicians.
• Smart upgrade option: Compatible with a Controlr module for WiFi control (sold separately) for remote monitoring and convenience.

Who It's For

The RE140iN is aimed at homeowners who want dependable hot water on demand without a bulky tank and who have access to qualified professional installation. It suits medium to larger households in warmer climates or where ground water temperatures are moderate, because customers report strong real-world performance in such conditions.

Those who should look elsewhere include buyers needing a condensing unit for maximum efficiency in cold-climate installations or anyone planning DIY installation; Rinnai and professionals recommend hiring a trained technician for proper setup and venting.

Pros & Cons

Pros

• Compact size that reclaims storage space while delivering solid hot water flow.
• Long residential warranty terms on the heat exchanger and clear serviceability improvements for technicians.
• Reliable operation reported by customers, including long service life when maintained properly.
• LED diagnostics and optional WiFi Controlr compatibility add convenience and easier troubleshooting.

Cons

• Non-condensing design is less efficient than condensing models in colder inlet water conditions.
• WiFi control module not included, and professional installation is recommended, adding to initial cost.

Specifications

Model	RE140iN
Fuel Type	Natural gas
Max Flow Rate	Up to 5.3 GPM
Heat Output	140,000 BTU
Installation	Indoor
Warranty (residential)	15-yr heat exchanger, 5-yr labor, 1-yr parts

Our Verdict

The Rinnai RE140iN is a strong value for homeowners who need reliable, space-saving on-demand hot water and who will use a qualified installer. It trades some condensing efficiency for simpler installation and proven durability, making it a practical choice for many warm-to-moderate climate households.

Frequently Asked Questions

Can this unit handle multiple showers at once?
At up to 5.3 GPM, it can support several fixtures simultaneously in many homes, though exact performance depends on inlet temperature and fixture flow rates.

Is WiFi control included?
The unit is compatible with a Rinnai Controlr for WiFi, but that module is not included and must be purchased separately.

Do I need a professional to install it?
Yes, professional installation is recommended; Rinnai provides a Find a Rinnai PRO resource to locate qualified technicians.