Rheem RTEX-27 240V Tankless Water Heater — On-Demand Hot Water

Overview

The Rheem RTEX-27 is a compact residential tankless electric water heater designed to deliver hot water on demand without a storage tank. With three heating chambers and a digital control interface, this unit supports a single point‑of‑use setup or lightweight multi‑fixture configurations in tight spaces.

Precise temperature control at a glance

External digital thermostat with an LED display provides clear, easy adjustments with near‑instant feedback. The readout helps you set the exact warm to hot level you prefer, reducing guesswork and increasing comfort.

Smart heating for variable demand

Advanced self‑modulation continuously tunes power in real time to match hot water demand. This adaptive approach aims to keep a steady supply while optimizing energy use across typical flows and temperature targets.

Durable, serviceable design

The unit employs copper immersion heating elements arranged across three chambers for robust heat transfer. All three elements are field serviceable, making on‑site maintenance feasible if needed.

Easy installation and future‑proofing

Designed with bottom 3/4 inch NPT water connections and threaded components, the RTEX‑27 is approachable for installer setups and future upgrades. Its compact footprint helps it fit within closets, under sinks, or other tight installations in homes and apartments.

Real‑world benefits and use cases

In everyday homes, you may enjoy a quick, comfortable shower after a brisk morning routine, or steady hot water while running a sink and a separate faucet in close succession. The RTEX‑27 is well suited for spaces where you value direct access to hot water without the overhead of a storage tank.

Note that results depend on your home’s hot water demand, inlet water temperature, and electrical setup. This model offers flexible operation that can align with various plumbing and electrical constraints.

Key features at a glance

• External digital thermostat with LED display for precise control
• Self‑modulation adjusts power to meet hot water demand
• Copper immersion heating elements across three chambers for reliable heat transfer
• Bottom 3/4 inch NPT water connections for straightforward installation
• Threaded design and clear temperature display for easy maintenance

What you can expect

Consider the RTEX‑27 when you want a space‑efficient, on‑demand hot water solution that adapts to changing usage patterns. It’s a practical option for residences with moderate hot water needs where you value control, speed, and comfort without sacrificing space.

Care and maintenance tips

Because heating elements are field‑serviceable, a qualified technician can replace components on site. Regularly verify connections and temperature settings to help sustain consistent performance over time.