Rheem 18kW Electric Instantaneous Water Heater

The Rheem 18kW Electric Instantaneous Water Heater is a Rheem Professional Classic electric tankless water heater for whole-home / multi-application domestic hot water applications. The RTEX-18 model provides 18 kW electric output and is designed to heat water on demand without a storage tank.

Rheem’s tankless electric line includes compact point-of-use and whole-home models with digital temperature control on larger models, durable metal housings, and no combustion venting requirements. Electrical sizing is critical because each kW model requires the specified voltage, amperage, breaker, and wire configuration.

Product Features:

• RTEX-18 / 18 kW Output: Model-specific Rheem electric tankless unit with 18 kW heating capacity.
• 240V Electrical Requirement: Specification chart lists 240V operation with 75A current draw.
• (2) 40A breakers Required: Breaker configuration from Rheem literature must be matched during installation.
• 14-1/2"" H x 18-1/4"" W x 3-1/2"" D Cabinet Size: Compact wall-mounted dimensions support installation near the point of use or in utility areas.
• On-Demand Heating: Heats water only during hot water flow, eliminating standby tank heat loss.
• No Gas Venting: Electric operation requires no combustion air or flue venting.
• Temperature-Controlled Operation: Rheem tankless electric models feature adjustable temperature control appropriate to the model class and application.

Warranty

Rheem Professional Classic tankless electric literature lists a 5-year heating chamber warranty and 1-year parts warranty. Verify current terms and installation requirements with Rheem documentation.