10 Orbek 18kw Tankless Water Heater Review of 2026 For Continuous Flow

1

18kW Tankless Water Heater Electric, ORBEK Instant On Demand Hot

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  9.7
• Brand
  Orbek

Key specs2

Panel and Breaker Demands

• Requires at least 150-amp household service panel
• Demands two dedicated 40A double-pole breakers
• Needs two sets of 8 AWG wiring with ground

Rated Flow Capacity

Up to 4.17 GPM across 2-3 fixtures

Pros & cons43

Pros

• Delivers up to 4.17 GPM to supply hot water for two to three fixtures simultaneously
• High-speed internal chip modulates power 20,000 times per second to keep output within 1 degree Fahrenheit
• Water and electricity separation design protects heating components from direct contact to reduce scale buildup
• Includes built-in dry-heating prevention, leakage shutoff, and lightning resistance with ETL certification

Cons

• Requires an electrical service panel of at least 150 amps with two dedicated 40-amp double-pole breakers
• Needs two separate runs of 8 AWG wiring rather than a single cable feed
• Weighs 18.3 pounds, making it heavier than most compact 18kW alternatives

2

Tankless Water Heater Electric 18kW 240V On-Demand Instant Hot Water

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  9.6
• Brand
  Garvee

Key specs2

Mounting Flexibility

Can be mounted vertically or horizontally to fit tight under-sink spaces or small utility closets where rigid plumbing restricts standard layouts.

Enclosure Construction

Corrosion-resistant stainless steel housing

Pros & cons42

Pros

• Stainless steel casing and heating elements offer enhanced durability over plastic alternatives
• Flexible wall-mount chassis permits vertical or horizontal orientation to fit cramped plumbing layouts
• Wide digital temperature adjustment spans from 86 to 140 degrees Fahrenheit via clear front controls
• Self-modulating power output prevents unnecessary energy draw during low-demand fixture use

Cons

• Listing omits specific maximum GPM flow ratings, requiring verification for high-demand setups
• Listing does not specify breaker amperage or required wire gauge sizes before purchasing

3

ORBEK RV Tankless Water Heater, Propane, 12V DC, For RV

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  9.5
• Brand
  Orbek

Key specs2

Power and Fuel Type

Liquid propane burner with 12V DC ignition

High-Altitude Capability

Engineered with staged combustion and an oxygen-free copper heat exchanger to maintain steady water temperatures up to 9,800 feet elevation.

Pros & cons43

Pros

• Operates on liquid propane and 12V DC power specifically designed for RVs and campers
• Rated for high-altitude performance up to 9,800 feet with staged combustion and brushless DC fans
• Integrated 150 PSI pressure-reducing valve eliminates the need to buy an external regulator
• Wired remote control adjusts temperature from 95 to 123 degrees Fahrenheit and displays error codes

Cons

• Unsuitable for residential 240V home electrical panels because it requires propane and 12V DC
• RV exterior door panels in matching colors must be purchased separately
• Heavier than electric models at 20.5 pounds and limited to a 123-degree Fahrenheit maximum output

4

18kw Tankless Water Heater Electric 240v for Whole House

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  9.1
• Brand
  Orbek

Key specs2

Electrical Hookup Specs

• Maximum current draw reaches 75 amps at 240V
• Requires 2 x 40-amp double-pole breakers
• Demands two runs of 8/2 AWG wire with ground

Plumbing Port Size

Standard 3/4-inch NPT water connections

Pros & cons42

Pros

• Delivers rapid heating reaching set temperatures up to 140 degrees Fahrenheit within seconds
• Uses standard 3/4-inch NPT plumbing connections for simple integration with household supply lines
• Compact wall-mount footprint at 13 by 17 inches frees up floor space in tight utility areas
• Self-modulating control drops power draw instantly when water flow decreases to prevent energy waste

Cons

• High 75-amp maximum draw requires two double-pole 40A breakers and two separate 8/2 AWG wire runs
• Manufacturer does not publish an explicit maximum GPM flow rate for cold-climate calculations

5

CAMPLUX Tankless Electric Water Heater 18kW, On Demand Hot Water

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  8.7
• Brand
  CAMPLUX ENJOY OUTDOOR LIFE

Key specs2

Activation Flow Rate

0.66 GPM minimum trigger threshold

Thermostat Range and Dial

Rotary knob provides smooth adjustment between 80 and 140 degrees Fahrenheit without needing to step through digital menus.

Pros & cons42

Pros

• Clear 0.66 GPM minimum activation flow ensures reliable burner engagement on moderate water pressure
• Continuous 360-degree rotating dial provides simple temperature tuning from 80 to 140 degrees Fahrenheit
• Standard 3/4-inch NPT water inlet and outlet align with standard residential plumbing lines
• Built-in water-electricity separation protects internal heating elements from premature scale accumulation

Cons

• Low-flow fixtures running under 0.66 GPM will not trigger heating elements to turn on
• Demands two double-pole 40A breakers and dual 8 AWG lines, requiring ample space in the main panel

6

VEVOR Tankless Water Heater Electric, 18KW 240V Black Instant Water

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  8.5
• Brand
  VEVOR

Key specs2

User Interface and Controls

IMD touch screen with child security lock

Core Heating Element

Built with a cast aluminum heat exchanger that isolates electrical components from water channels to minimize scale buildup.

Pros & cons42

Pros

• Lightweight 11.68-pound frame makes wall mounting straightforward even in tight utility closets
• Cast aluminum heating chamber isolates water pathways from electrical components to resist corrosion
• Integrated child security lock on the IMD touch screen prevents unintended temperature adjustments
• Digital LED display provides clear readout across the full 86 to 140 degrees Fahrenheit operating range

Cons

• Product listing does not specify a maximum GPM output, requiring manual verification before buying
• Requires dual 40-amp circuit breakers and two runs of 8 AWG wiring that may strain older breaker boxes

7

Midea 18KW Electric Tankless Water Heater, 240V, On-demand Hot Water,

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  8.0
• Brand
  Midea

Key specs2

Smart Connectivity

Wi-Fi app control via Smart Home App

Chassis Weight

9.48 lbs ultra-compact profile

Pros & cons42

Pros

• Wi-Fi enabled Smart Home app connectivity allows temperature adjustment and status monitoring from a phone
• Lightweight 9.48-pound chassis makes one-person wall mounting quick and painless
• Intuitive front touch panel provides direct manual temperature overrides with real-time status feedback
• Self-modulating heating design matches electrical draw strictly to actual flow demand

Cons

• Product listing omits wiring gauge, breaker counts, and flow rates, requiring verification before purchase
• Smart app features depend on an active home Wi-Fi network to maintain remote functionality

8

18kW Tankless Water Heater Electric 240V WINTEMP, On Demand Instant

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  7.9
• Brand
  WINTEMP

Key specs2

Peak Output Flow

Up to 4.3 GPM for 2-3 bathroom homes

Warranty Coverage

2-year limited manufacturer warranty

Pros & cons42

Pros

• Generates a robust maximum flow rate of 4.3 GPM to support simultaneous showers in mild climates
• Built-in Wi-Fi connectivity lets users adjust output temperature remotely without visiting the utility room
• Backed by a 2-year limited manufacturer warranty with listed ETL safety certification
• Self-modulating power management cuts idle electricity use completely when taps are closed

Cons

• Requires an electrical service panel of at least 150 amps to prevent overload when other appliances run
• Demands two dedicated 40-amp double-pole breakers and dual 8/2 AWG wire runs

9

Rheem 18kW 240V Tankless Electric Water Heater, Gray

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  7.9
• Brand
  Rheem

Key specs2

Heating Element Serviceability

Dual threaded copper immersion elements can be individually accessed and serviced in the field without replacing the entire unit.

Max Flow Delivery

Up to 4.4 GPM continuous output

Pros & cons42

Pros

• Delivers the highest stated flow in its class at up to 4.4 GPM for consistent multi-tap performance
• Dual copper immersion heating elements are threaded and field-serviceable for straightforward replacement
• Bottom-mounted 3/4-inch NPT plumbing ports simplify direct drop-in piping configurations
• Digital thermostatic control regulates water temperature with tight 1-degree precision

Cons

• Copper immersion elements sit directly in water and require periodic descaling in hard water areas
• Listing does not state breaker or wire gauge requirements, requiring verification in product documentation

10

14kW Tankless Water Heater Electric ORBEK On Demand Heater 240V

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  7.1
• Brand
  Orbek

Key specs2

Single-Breaker Installation

Runs on a single 60A double-pole breaker and one 6 AWG wire run, making it ideal for breaker panels with limited free slots.

Plumbing Port Size

1/2-inch NPT connections

Pros & cons42

Pros

• Requires only a single 60-amp double-pole breaker and one 6 AWG wire set, saving panel breaker slots
• Compact 9.5 by 9.5-inch Pearl housing fits inside smaller utility spaces than 18kW units
• Delivers up to 3.38 GPM of on-demand hot water suitable for single-bath homes or targeted points of use
• Internal chip monitors and regulates heat 20,000 times per second for stable output within 1 degree

Cons

• Maximum 3.38 GPM flow rate cannot support two high-flow showers simultaneously in cold groundwater areas
• Employs 1/2-inch NPT water ports instead of standard 3/4-inch connections, requiring pipe adapters

Last update on 2026-10-08 / Affiliate links / Images, Product Titles, and Product Highlights from Amazon Product Advertising API

Can the Orbek 18kW tankless water heater run two showers at the same time?

Yes, the Orbek 18kW provides up to 4.17 GPM of continuous hot water, which is designed to supply 2 to 3 fixtures simultaneously. Whether that output supports two showers running at once depends on your incoming groundwater temperature and showerhead flow rates. In warmer regions where incoming water requires less heating, it easily manages multiple fixtures, while colder winter groundwater will reduce the total simultaneous flow available.

What electrical panel and breaker setup does the Orbek 18kW require?

The 240-volt Orbek 18kW requires two 40-amp double-pole circuit breakers and two separate wiring runs using 8 AWG wire with ground. At full heating demand, the unit pulls a maximum of 75 amps. Your home should have at least a 150-amp main electrical service panel to support this dedicated draw without tripping your main breaker when other household appliances run.

Does the Orbek 18kW maintain a steady temperature when other taps open?

Yes, the heater uses self-modulating technology designed to maintain output within 1 degree Fahrenheit of your chosen temperature setting. Internal controls monitor water flow and automatically adjust power consumption as taps turn on or off. When water demand drops or stops completely, power consumption dials down immediately, drawing zero electricity when fixtures are shut.

What plumbing connections and wall clearance does the unit require?

The heater connects using standard 3/4-inch NPT water fittings for direct hookup to existing household plumbing lines. The casing measures approximately 3.9 inches deep, allowing flush wall mounting that frees up floor space previously occupied by a conventional storage tank. You should confirm exact unit measurements on the specific product listing, as dimensions vary between 3.9 inches and 13 inches wide across different production runs.

How does the Orbek 18kW compare to models from Rheem and Midea?

All three brands provide 18kW of on-demand 240-volt heating for multi-fixture use, but their interface features differ. Rheem includes an external digital thermostatic control with an LED display accurate to 1 degree. Midea incorporates smart home app control to adjust and customize temperatures remotely from a smartphone. Orbek focuses on core demand heating, providing an ETL-certified build with straightforward digital controls for homeowners who want consistent hot water without app connectivity.

How do you prevent electrical panel overloads when installing an 18kW heater?

Confirm that your breaker box has at least 150-amp service capacity and two open double-pole breaker slots before installation. Because an 18kW tankless unit draws up to 75 amps at peak output, running several large appliances at the same time can strain an older panel. Managing heavy electrical loads across your home, such as plugging in a low-wattage space heater for shared circuits or using a room heater with low power consumption in living areas, helps keep total household demand well within safe electrical limits.