As Amazon Associates, we earn from qualifying purchases. This means we may receive a small commission at no extra cost to you if you click through and make a purchase.
As an Amazon Associate we earn from qualifying purchases. Links on this page are affiliate links.
The NOVIEEX 18 kW 4.9 GPM Tankless Water Heater delivers high flow for multi-fixture households. It features precise 1°F temperature adjustments and a 99.8% thermal efficiency rating. If you need these specific specs, this unit fits well. However, you might look for novieex 18 kw 4 9 gpm alternatives if you require a smaller footprint or smart connectivity. Some buyers prefer brands with different safety certifications or WiFi controls.
We selected 6 alternatives that share the same 18 kW heating capacity and 240V electrical requirements. These options overlap with the original’s core performance metrics while offering distinct physical dimensions or feature sets. For example, some models prioritize compact size for tight installations. Others emphasize digital displays or remote monitoring capabilities. This list helps you compare tankless water heaters based on published specifications. You can choose a unit that matches your home’s electrical infrastructure and spatial constraints without compromising on essential hot water performance.
01 How the alternatives compare
Thermomate 18kW Electric Tankless Water Heater
The Thermomate 18kW model matches the NOVIEEX power at 18 kW and 240V. It differs in physical dimensions, measuring 13.1 inches wide and 17.1 inches tall. This makes it slightly larger and deeper than the NOVIEEX unit. You get a similar heating capacity for whole-house use. The Thermomate focuses on reliable performance and precise temperature management. It suits homes with strong electrical infrastructure. If you prefer a gray finish and do not mind the extra footprint, this is a solid alternative. It offers the same energy efficiency without the highest flow rate on the list.
APUS 18kW 4.4 GPM Tankless Water Heater
The APUS 18kW heater provides 4.4 GPM, which is lower than the NOVIEEX 4.9 GPM. It shares the 18 kW power and 240V requirement. The APUS model is more compact, measuring 11.4 inches wide and 13.7 inches tall. It weighs 15.2 pounds. You get an LED display for precise digital control. This unit prioritizes temperature accuracy over maximum flow speed. It is a good choice for users who value efficiency and precise adjustments. If you have the electrical capacity for dual breakers and need a smaller unit, the APUS fits well. It sacrifices some flow rate for a tighter footprint.
Orbek 18kW 240V Tankless Electric Water Heater
The Orbek 18kW heater offers the same 18 kW power and 240V voltage. It stands out for its compact size, measuring only 8 inches wide and 11 inches tall. This is significantly smaller than the NOVIEEX model. It is designed for point-of-use or compact whole-house installations. You give up maximum flow rate for this space-saving design. The Orbek is ideal for buyers who prioritize a small footprint and safety certifications. It fits well in tight spaces where the NOVIEEX would not. If you need solid 18 kW power in a minimal package, this unit is a practical choice.
WINTEMP 18 kW Tankless Water Heater with WiFi
The WINTEMP 18kW WiFi model shares the 18 kW power and 240V voltage. It includes WiFi connectivity for remote control, a feature not listed for the NOVIEEX. The unit measures 11.1 inches wide and 4 inches deep, making it very thin. It weighs 12 pounds. You get ETL safety certification and digital feedback. This model is best for users who prioritize remote control and mild climate performance. It fits homes with adequate electrical capacity. If you want modern connectivity and a slim profile, this WINTEMP option is worth considering. It offers similar heating power with added smart features.
SIVUATEK 18kW Electric Tankless Water Heater
The SIVUATEK 18kW heater provides the same 18 kW power and 240V voltage. It is designed for whole-house installations with precise LED controls. The unit measures 12.2 inches wide and 17.3 inches tall. It is slightly wider and taller than the NOVIEEX model. You get ETL certification and high efficiency for multiple bathrooms and kitchens. This unit suits households needing reliable hot water with precise temperature management. If you prefer a gray finish and do not mind the larger size, this is a strong alternative. It offers similar performance with a focus on whole-house reliability and safety.
WINTEMP 18kW Electric Tankless Water Heater
The second WINTEMP 18kW model shares the 18 kW power and 240V voltage. It measures 9.7 inches wide and 14 inches tall, making it narrower than the NOVIEEX. It weighs 12 pounds. This unit includes an LED display and ETL certification. It is designed for homes with dual 40-amp breakers. You get solid safety and flow for specific electrical setups. This model fits users who prioritize digital feedback and certification over maximum flow speed. If you need a narrower unit for tight spaces, this WINTEMP option is practical. It offers similar heating power with a more compact width.
| # | Product | Best for | Price |
|---|---|---|---|
| 1 | NOVIEEX 18 kW 4.9 GPM Tankless Water Heater Best overall | high-flow multi-fixture households | |
| 2 | Thermomate 18kW Electric Tankless Water Heater Best premium | homes with strong electrical capacity | |
| 3 | APUS 18kW 4.4 GPM Tankless Water Heater Also great | precise temperature control and efficiency | |
| 4 | Orbek 18kW 240V Tankless Electric Water Heater Best budget | Compact whole-house installations | |
| 5 | WINTEMP 18 kW Tankless Water Heater with WiFi Also great | WiFi-enabled whole-house heating needs | |
| 6 | SIVUATEK 18kW Electric Tankless Water Heater Also great | Whole-house hot water with precise temp control | |
| 7 | WINTEMP 18kW Electric Tankless Water Heater Also great | homes with dual 40-amp breakers needing 4.3 GPM |
NOVIEEX 18 kW 4.9 GPM Tankless Water Heater
Best for: high-flow multi-fixture households
- Fuel Type
- Electric
- Max Flow Rate
- 4.9 GPM
- Heating Capacity
- 18kW
- Installation Location
- Indoor
- Voltage
- 240V
- Fixture Capacity
- 2-3 Points
The NOVIEEX 18kW electric tankless water heater delivers up to 4.9 GPM at 240V. It supports 2-3 simultaneous fixtures with an adjustable temperature range of 77°F to 140°F. The unit measures 11.1 inches wide by 15.9 inches high. It features an LED display and 99.8% thermal efficiency. This model suits small-to-medium homes needing high flow rates.
- Delivers a maximum flow rate of 4.9 GPM
- Adjustable temperature in 1°F increments from 77°F to 140°F
- 99.8% thermal efficiency eliminates standby energy waste
- Compact wall-mount design measures 11.1 by 15.9 inches
- Requires 2 sets of 8 AWG wires and 2 × 40A breakers
- Limited to indoor installation only
- Includes only a 1-year warranty
- You need a high flow rate of 4.9 GPM for multiple fixtures
- You want precise temperature control in 1°F steps
- You have the electrical capacity for 2 × 40A double-pole breakers
- You require outdoor installation capabilities
- You need a warranty longer than 1 year
- Your electrical system cannot support 75A maximum current
Verdict: NOVIEEX 18kW 4.9 GPM Electric Heater offers the highest flow rate on this list for homes requiring simultaneous multi-fixture use. It fits buyers who prioritize precise temperature adjustments and have the necessary heavy-duty electrical infrastructure installed.
Thermomate 18kW Electric Tankless Water Heater
Best for: homes with strong electrical capacity
- Fuel Type
- Electric
- Max Flow Rate
- Up to 4.4GMP
- Heating Capacity
- 18kW
- Installation Location
- Indoor
- Voltage
- 240 Volt
- Temperature Range
- 80°F to 140°F
This ThermoMate unit delivers 18 kW of heating power at 240 volts. It provides hot water in three seconds with a flow rate up to 4.4 GPM. The device features a digital display for temperature adjustments between 80°F and 140°F. Its compact wall-mounted design saves space. You get ETL certification for safety. This model suits households needing efficient, on-demand hot water without a storage tank.
- 18 kW heating capacity for rapid hot water delivery
- Flow rate up to 4.4 GPM
- Digital display with 1°F adjustment increments
- ETL certified for safety standards
- 99.8% energy efficiency rating
- Requires two 40-amp double-pole breakers
- Maximum current draw of 76 amps
- Fixed indoor installation location only
- You need a compact unit for tight spaces
- You want precise temperature control via a digital display
- You have the electrical capacity for 76 amps
- You only have a single 40-amp breaker available
- You need an outdoor installation option
- You prefer a flow rate above 4.4 GPM
Verdict: ThermoMate 18kW Electric Tankless Heater offers reliable performance for users with adequate electrical infrastructure. It fits homes prioritizing energy efficiency and precise temperature management over higher flow rates.
APUS 18kW 4.4 GPM Tankless Water Heater
Best for: precise temperature control and efficiency
- Fuel Type
- Electric
- Max Flow Rate
- Up to 4.4 GPM
- Heating Capacity
- 18kW
- Installation Location
- Indoor
- Voltage
- 240V
- Fixture Capacity
- 2–3 Points
The APUS 18kW electric tankless water heater delivers up to 4.4 GPM for whole-house use. It features an 86–131°F digital range and 99.8% thermal efficiency. The slim 3.54-inch depth saves space. You get precise temperature control with memory. It requires 240V and two 40A breakers for installation.
- High flow rate of 4.4 GPM
- 99.8% thermal efficiency
- Precise 1°F digital control
- Slim 3.54-inch depth
- Lower max flow rate than 4.9 GPM competitors
- Heavier build at 15.2 pounds
- Requires two 40A breakers
- You want precise digital temperature settings
- You need a slim wall-mounted unit
- You require high thermal efficiency
- You need higher than 4.4 GPM flow
- You cannot install two 40A breakers
- You prefer a lighter unit under 15 pounds
Verdict: APUS 18kW 4.4 GPM Tankless Heater offers precise digital control and high efficiency for users who prioritize temperature accuracy over maximum flow speed. It suits those with the electrical capacity for dual breakers.
Orbek 18kW 240V Tankless Electric Water Heater
Best for: Compact whole-house installations
- Fuel Type
- Electric
- Max Flow Rate
- 4.22 GPM
- Heating Capacity
- 18 kW
- Voltage
- 240 V
- Fixture Capacity
- 2-3 Point of Use
- Installation Type
- Whole House
The Orbek 18kW unit delivers up to 4.22 GPM of hot water at 240V. It heats water in 3 seconds for continuous supply. The compact design measures 11 inches in height. It fits 2-3 points of use. ETL certification ensures safety. This model suits whole-house needs where space is limited. You get endless hot water without a bulky tank.
- 18 kW heating capacity for fast recovery
- 4.22 GPM maximum flow rate
- 3-second instant hot water delivery
- ETL certified for safety standards
- Compact 11-inch height saves wall space
- Lower flow rate than 4.3 or 4.4 GPM competitors
- Requires 75A total amperage and two 40A breakers
- Dimensions are 13 inches wide versus 8 inches in other models
- You need a compact unit that fits in tight spaces
- You require ETL certification for safety assurance
- You want instant hot water at 140℉
- You need a flow rate above 4.22 GPM
- You cannot install two 40A double-pole breakers
- You prefer a wider unit for easier mounting
Verdict: Orbek 18kW 240V Tankless Heater offers solid 18kW power in a smaller footprint. It fits buyers who prioritize compact size and safety certification over maximum flow rate.
WINTEMP 18 kW Tankless Water Heater with WiFi
Best for: WiFi-enabled whole-house heating needs
- Fuel Type
- Electric
- Max Flow Rate
- 4.3 GPM
- Heating Capacity
- 18kW
- Voltage
- 240V
- Installation Type
- Whole House
- Features
- Tankless
The WINTEMP WN18 is an 18kW electric tankless water heater designed for whole-house use. It delivers up to 4.3 GPM of hot water at 240V. The unit weighs 12 pounds and measures 11.1 by 19.1 by 4 inches. It features WiFi control and ETL certification. This model suits homes in mild climates needing steady shower temperatures without tank storage.
- 18kW heating capacity for continuous hot water
- Up to 4.3 GPM flow rate for showers
- WiFi remote control for temperature adjustment
- Compact 12-pound wall-mounted design
- ETL certified for safety compliance
- Lower flow rate of 4.3 GPM compared to the NOVIEEX 4.9 GPM
- Requires 150 Amp household service and dual 40 Amp breakers
- Limited to 2-year manufacturer warranty
- You need WiFi control for remote temperature settings
- You have a 150 Amp electrical service available
- You want an ETL certified unit for safety
- You require a flow rate above 4.3 GPM
- You cannot install dual 40 Amp breakers
- You need a warranty longer than 2 years
Verdict: WINTEMP 18kW 240V Tankless Heater fits users who prioritize remote WiFi control and ETL safety certification over maximum flow speed. It is a solid choice for mild climates with adequate electrical capacity.
SIVUATEK 18kW Electric Tankless Water Heater
Best for: Whole-house hot water with precise temp control
- Fuel Type
- Electric
- Heating Capacity
- 18kW
- Voltage
- 240V
- Fixture Capacity
- 3–4 simultaneous usage points
- Temperature Range
- 86°F to 131°F
- Installation Type
- Whole House
The SIVUATEK 18kW 240V electric tankless water heater delivers instant hot water for whole-house use. It features 99.8% thermal efficiency and supports 3–4 simultaneous usage points. You can set the temperature from 86°F to 131°F in 1°F increments via an LED display. This unit requires two 40-amp circuit breakers and measures 17.3 inches in height. It offers precise control and high efficiency for steady hot water output.
- 18kW heating power for instant hot water
- 99.8% thermal efficiency reduces energy loss
- LED display allows 1°F temperature adjustments
- Supports 3–4 simultaneous usage points
- ETL certified for safe operation
- Requires two 40-amp circuit breakers
- 17.3-inch height is bulkier than compact under-sink models
- Temperature range stops at 131°F
- You need whole-house hot water for multiple fixtures
- You have the electrical capacity for two 40-amp breakers
- You want precise temperature control in 1°F increments
- You only have a single 40-amp circuit available
- You require a lower maximum temperature than 131°F
- You need a unit smaller than 17.3 inches in height
Verdict: SIVUATEK 18kW 240V Electric Heater suits households needing reliable, high-efficiency hot water for multiple bathrooms and kitchens. Its precise LED controls and ETL certification make it a solid choice for whole-house installations with adequate electrical infrastructure.
WINTEMP 18kW Electric Tankless Water Heater
Best for: homes with dual 40-amp breakers needing 4.3 GPM
- Fuel Type
- Electric
- Max Flow Rate
- 4.3 GPM
- Heating Capacity
- 18kW
- Voltage
- 240V
- Fixture Capacity
- 2-3 points of use
- Features
- Tankless, LED Display
This WINTEMP unit delivers 18 kW of heating power at 240V, providing up to 4.3 GPM of hot water. It features an LED display and ETL certification for safety. The compact gray design measures 14 inches in height and weighs 12 pounds. It suits households needing endless hot water for two to three points of use simultaneously.
- 18 kW heating capacity for rapid hot water generation
- Max flow rate of 4.3 GPM supports multiple fixtures
- ETL certified with leakage and overheat protection
- LED display shows real-time temperature and settings
- Lower maximum flow rate of 4.3 GPM compared to the 4.9 GPM NOVIEEX model
- Requires two 40-amp double-pole breakers and specific 8/2 AWG wiring
- Height of 14 inches differs from the 19.1-inch variant listed in variations
- You need ETL certification for your installation
- You want an LED display for temperature monitoring
- You are installing a 240V system with dual 40-amp breakers
- You require a flow rate higher than 4.3 GPM
- You only have a single 40-amp breaker available
- You need a unit taller than 14 inches
Verdict: WINTEMP 18kW Electric Water Heater offers solid safety and flow for homes with the right electrical setup. It fits users who prioritize ETL certification and digital feedback over maximum flow speed.
02 Specifications side by side
| Spec | NOVIEEX 18 kW 4.9 GPM Tankless Water Heater | Thermomate 18kW Electric Tankless Water Heater | APUS 18kW 4.4 GPM Tankless Water Heater | Orbek 18kW 240V Tankless Electric Water Heater | WINTEMP 18 kW Tankless Water Heater with WiFi | SIVUATEK 18kW Electric Tankless Water Heater | WINTEMP 18kW Electric Tankless Water Heater |
|---|---|---|---|---|---|---|---|
| Fuel Type | Electric | Electric | Electric | Electric | Electric | Electric | Electric |
| Max Flow Rate | 4.9 GPM | Up to 4.4GMP | Up to 4.4 GPM | 4.22 GPM | 4.3 GPM | – | 4.3 GPM |
| Heating Capacity | 18kW | 18kW | 18kW | 18 kW | 18kW | 18kW | 18kW |
| Installation Location | Indoor | Indoor | Indoor | – | – | – | – |
| Voltage | 240V | 240 Volt | 240V | 240 V | 240V | 240V | 240V |
| Fixture Capacity | 2-3 Points | – | 2–3 Points | 2-3 Point of Use | – | 3–4 simultaneous usage points | 2-3 points of use |
| Temperature Range | 77°F to 140°F | 80°F to 140°F | 86–131°F | – | – | 86°F to 131°F | – |
| Installation Type | – | – | – | Whole House | Whole House | Whole House | – |
| Features | Tankless | Tankless | Tankless, LED Display | Tankless | Tankless | Tankless | Tankless, LED Display |
| Application | Bathroom | Shower | – | Point of Use | – | – | – |
| Form Factor | – | – | – | Compact | – | – | – |
| Wattage | 18 kW | 18 kW | 18 kW | 18 kW | 18 kW | 18 kW | 18 kW |
| Intended Use | – | – | – | Home | – | – | – |
| Dimensions | 11.1 × 11.1 × 15.9 inches | 13.1 × 13.1 × 17.1 inches | 11.4 × 11.4 × 13.7 inches | 8 × 8 × 11 inches | 19.1 × 11.1 × 4 inches | 12.2 × 12.2 × 17.3 inches | 9.7 × 9.7 × 14 inches |
| Weight | – | – | 15.2 pounds | – | 12 pounds | – | 12 pounds |
| Color | Silver | Gray | Gray | Snow | Gray | Gray | Gray |
| Model | DS-18 | ET180 | AP-ADSK180-H18 | HEU-ET018A5W-M0 | WN18 | TSB-180 | YQ-WN18K |
| Size | – | 240V/18kW | – | M-18 | 18kW | – | WN-18 |
03 Frequently asked questions
Which alternative offers the most compact size for small spaces?
The Orbek 18kW model is the most compact option on this list. It measures just 8 inches wide and 11 inches tall. This smaller footprint makes it ideal for tight installations where space is limited. You get the same 18 kW power output in a significantly smaller package compared to other 18 kW units.
Can I control my water heater remotely with WiFi?
Yes, the WINTEMP 18kW 240V model includes WiFi connectivity for remote control. This feature allows you to adjust settings from your phone. It is designed for whole-house heating needs and includes ETL safety certification. This option suits users who prioritize digital convenience and remote management over maximum flow speed.
Do any of these heaters have a digital display?
Two models feature LED displays for precise temperature monitoring. The APUS 18kW unit includes an LED display for clear feedback. The WINTEMP 18kW Electric model also has an LED display. These screens help you track water temperature accurately. You get digital visibility into your heating settings on these specific units.
Which unit is best for whole-house installations?
The Orbek, WINTEMP, and SIVUATEK models are all intended for whole-house use. The Orbek is noted for compact whole-house installations. The WINTEMP WiFi model supports whole-house heating needs. The SIVUATEK unit is also designed for whole-house hot water supply. These options provide the necessary power for multiple fixtures throughout your home.
How wide is the Thermomate compared to the NOVIEEX?
The Thermomate 18kW model is wider than the NOVIEEX unit. It measures 13.1 inches in width. The NOVIEEX model is 11.1 inches wide. This difference means the Thermomate has a larger physical footprint. You need to account for this extra width during your installation planning.
Is there a model with a very slim profile?
The WINTEMP 18kW 240V model has a notably slim profile. It is only 4 inches tall, though it is longer at 19.1 inches. This low height allows for discreet installation in tight vertical spaces. You get a standard 18 kW output in a form factor that is much shorter than typical tankless heaters.
Which heater is best for precise temperature control?
The APUS 18kW model is highlighted for precise temperature control and efficiency. It offers digital control for accurate temperature adjustments. The SIVUATEK unit also features precise LED controls for reliable management. These models suit households that prioritize exact temperature accuracy over maximum flow speed.
