Paperwork says it requires four 40 amp breakers or two DP 40 amp breakers. Max draw of 75 amps.

Rheem RTEX-18 18kW 240V Electric Tankless Water Heater, Small, Gray

Rheem RTEX-18 18kW 240V Electric Tankless Water Heater, Small, Gray

Q: will this supply two showers, washer and dishwasher for two people? (1000 sf house)

Hello- Sizing an electric tankless is very difficult. I always recommend that you call Rheem at 800-432-8373 to get a suggestion. I want to say this will only keep up with ONLY 1 source of hot water at any one given time. That being said, the RTEX-18 performance ( @240V )- 1.5GPM - 82degree rise 2.0GPM - 62degree rise 2.5GPM - 49degree rise 3.0GPM - 41degree rise So.... what it can keep up with all depends on: -the temp of water coming into the house -the flow rate of each faucet/shower head/washing machine/source of hot water -outlet temp desired I hope this helped :) Ben

Q: Rheem rtex-18 be big enough to heat water in my shop to wash my hands and perhaps take a shower in kansas city, mo?

Yes you could even go with the unit rtex-15 one smaller if that's it. Good luck

Q: how many breakers and what amp.

The RTEX-18 (240 Volt) requires (2) 40 amp breakers and 8 AWG wire.

Product ID: 724817007

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Details

Brand
Rheem
Product Dimensions
36.8W x 46.4H
Special Feature
LED Display
Color
gray
Wattage
18000 W

⚡18kW high power output

💧Up to 4.4 GPM flow rate

📟±1°C precision digital temp control

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Description

🔥 Hot water, zero wait — power your lifestyle with precision! ⚡

COMPACT SPACE SAVER - 90% smaller than traditional tanks—perfect for sleek, modern homes where every inch counts.
ENDLESS HOT WATER ON DEMAND - Never run out during your morning routine with continuous flow up to 4.4 gallons per minute.
ENERGY SMART SELF MODULATION - Automatically adjusts power to your exact hot water needs, slashing energy waste by up to 50%.
PRECISION TEMPERATURE CONTROL - External LED display with ±1 degree accuracy puts you in total command of your hot water experience.
EFFORTLESS INSTALLATION MAINTENANCE - 3/4" NPT bottom water connection and easy-to-replace heating elements make setup and upkeep a breeze.

The Rheem RTEX-18 is a compact, 18kW 240V electric tankless water heater designed for efficient, on-demand hot water delivery. Featuring a precise digital temperature control with LED display, durable copper heating elements, and advanced self-modulating technology, it provides up to 4.4 GPM flow rate while saving up to 50% on energy costs. Its sleek, space-saving design and easy installation make it ideal for modern homes seeking reliable, endless hot water without the bulk of traditional tanks.

Specifications

Brand	Rheem
Model Number	RTEX-18
Product Dimensions	36.83 x 36.83 x 46.36 cm; 6.7 kg
Color	gray
Name List for Name Plates	Heater
Wallpaper Pattern	ミニマリスト、モダン
Voltage	240 Volts
Wattage	18000 W
Laser Class	LED Display
Included Components	Fitting Aerator
Are Batteries Included	No
Model Year	2016
Item Weight	6.7 Kilograms

Have a Question? See What Others Asked

will this supply two showers, washer and dishwasher for two people? (1000 sf house)

How many amps

Rheem rtex-18 be big enough to heat water in my shop to wash my hands and perhaps take a shower in kansas city, mo?

how many breakers and what amp.

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