Best 36 kW Tankless Water Heaters: 15 Spec-Based Picks
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Finding the best 36 kW tankless water heaters requires matching high output to your home’s electrical capacity. We compared 15 models based strictly on the specifications published on their listings. The Stiebel Eltron Tempra 36 Trend leads because it delivers 36 kW of modulated electric heating across a broad temperature range. This unit supports whole-house heating without venting if your service panel handles 300 amps. Other picks include WiFi-enabled models and compact units for under-sink use. This guide helps you decide which heater fits your flow rate needs and breaker space.
Our top pick: Stiebel Eltron Tempra 36 Trend Tankless Water Heater.
Quick picks
The best fit for you
- You want the most compact model on the list EcoSmart 36 kW Electric Tankless Water Heater The EcoSmart ECO 36 is only 3.6 inches deep, fitting tight spaces.
- You need smart control in multi-bathroom homes WINTEMP 36kW Electric Tankless Water Heater The WINTEMP WN36 includes WiFi for mobile app adjustments and monitoring.
- You want high multi-bath flow rates Atmor 36kW 7.03 GPM Tankless Water Heater The Atmor AT-36N-XTP delivers a high 7.03 GPM output for demand.
- You prefer manual external temperature control Rheem 36 kW Electric Tankless Water Heater The Rheem RTEX-36 uses straightforward dial-based adjustments instead of digital features.
Our 15 picks
Stiebel Eltron Tempra 36 Trend Tankless Water Heater
Best for: whole-house electric heating with 300 A panels
- Wattage
- 36 kW (what this guide is about)
- Fuel Type
- Electric
- Voltage
- 240 V
- Temperature Control
- 68° to 140°F
- Dimensions
- 14.5 x 16.6 x 4.63 in
- Use
- Whole House
View on Amazon: Stiebel Eltron Tempra 36 Trend Tankless Water Heater
The Stiebel Eltron Tempra 36 Trend is a 36 kW, 240V electric tankless water heater designed for whole-house use. It provides on-demand hot water with an adjustable output between 68°F and 140°F. The unit features auto-modulating copper heating elements and requires a 300 A electrical service. It fits your home if you need high-capacity electric water heating without venting.
Pros
- Output water temperature adjustable from 68°F to 140°F
- Solid copper interior heating system with auto-modulation
- Digital temperature display with silent operation
- Includes 7-year leakage and 3-year parts warranties
Cons
- Requires a minimum 300 A electrical service
- No wireless connectivity or remote control listed
Good fit if
- You have an electrical panel that supports 300 A service.
- You need output water temperatures reaching up to 140°F.
- You want a whole-house unit that requires no venting.
Skip if
- You have an electrical service panel under 300 A.
- You want smart features or WiFi connectivity built into the unit.
Verdict: Stiebel Eltron Tempra 36 Trend Tankless Water Heater delivers 36 kW of modulated electric heating across a broad 68°F to 140°F range. It provides whole-house capacity without venting if your home supports 300 A service.
WINTEMP 36kW Electric Tankless Water Heater
Best for: smart control in multi-bathroom homes
- Wattage
- 36 kW (what this guide is about)
- Fuel Type
- Electric
- Flow Rate
- 8.7 GPM
- Voltage
- 240 V
- Certification
- ETL
- Dimensions
- 21.5" H × 13.7" W × 5.2" D
This 36 kW electric tankless water heater delivers on-demand hot water with a maximum flow rate of up to 8.7 GPM at 240 volts. It features built-in WiFi control, allowing you to manage temperature settings from your smartphone. Designed for homes with three to five bathrooms in mild to moderate climates, it requires a 150-amp electrical draw across four 40-amp double-pole breakers and 3/4-inch NPT connections.
Pros
- Delivers a maximum flow rate of up to 8.7 GPM
- Built-in WiFi allows temperature adjustments via smartphone
- Self-modulating technology adjusts power output to flow demand
- Equipped with dry-fire, overheat, and electrical leakage protections
Cons
- Demands four dedicated 40A double-pole breakers and four 8/2 AWG cables
- Manufacturer recommends a 300A household electrical service
Good fit if
- You want smartphone WiFi control for setting water temperatures.
- You supply hot water to three to five bathrooms in a mild or moderate climate.
- Your home electrical system can handle a 150-amp peak draw.
Skip if
- You have an electrical panel with less than the recommended 300A service.
- You prefer an offline unit without smart or WiFi functionality.
Verdict: WINTEMP 36 kW Electric Tankless Water Heater with WiFi provides high flow capacity alongside mobile app adjustments. It suits high-demand households equipped with the recommended 300A electrical service.
WINTEMP 36 kW WiFi Tankless Water Heater
Best for: homes wanting smart monitoring and high flow
- Wattage
- 36 kW (what this guide is about)
- Fuel Type
- Electric
- Flow Rate
- 8.7 GPM
- Voltage
- 240V
- Temperature Control
- 86°F to 140°F
- Certification
- ETL
This 36 kW electric unit supplies up to 8.7 GPM of hot water at 240 volts, supporting three to five fixtures at once. It connects via Wi-Fi for remote temperature adjustments between 86°F and 140°F, while tracking power and water usage in real time. It suits homes needing high flow rates that also want mobile controls and automatic flow regulation to prevent temperature drops.
Pros
- Delivers up to 8.7 GPM for three to five simultaneous fixtures
- Wi-Fi connectivity enables remote temperature adjustments and usage tracking
- Internal flow control reduces volume automatically to maintain temperature
- Cast-aluminum heating system with dry-fire and overheat protection
Cons
- Requires a 150-amp electrical supply across four 40-amp double-pole breakers
- Needs four separate sets of 8 AWG wiring for installation
Good fit if
- You need high output up to 8.7 GPM across multiple simultaneous fixtures.
- You want Wi-Fi monitoring for tracking water and electricity consumption.
- You have panel capacity for a 150-amp, 240-volt electrical installation.
Skip if
- You cannot accommodate four double-pole 40-amp breakers in your service panel.
- You prefer a lighter unit than this 38-pound chassis.
Verdict: WINTEMP 36 kW WiFi Tankless Water Heater delivers high 8.7 GPM output paired with app-based power tracking and automatic temperature stabilization. Its demanding 150-amp electrical requirement requires dedicated breaker space and heavy wiring.
VEVOR 36kW Touchscreen Electric Tankless Water Heater
Best for: homes with high-amperage electrical panels
- Wattage
- 36 kW (what this guide is about)
- Fuel Type
- Electric
- Voltage
- 240V
- Temperature Control
- 30-60°C / 86-140°F
- Dimensions
- 13.7 x 13.7 x 5.31 inches
- Weight
- 34 pounds
View on Amazon: VEVOR 36kW Touchscreen Electric Tankless Water Heater
The VEVOR 36kW Touchscreen Electric Tankless Water Heater provides on-demand heating via a 240V electrical connection. It features an LCD touch screen with a digital temperature range of 86°F to 140°F and standard 3/4-inch NPT plumbing ports. The die-cast aluminum design isolates water from electrical components. This unit suits you if you need high-output residential or light commercial heating and have panel capacity for four 40-amp circuit breakers.
Pros
- Die-cast aluminum heating element separates water from electrical paths
- LCD touch screen with digital controls and safety lock
- Adjustable temperature range from 86°F to 140°F
- Standard 3/4-inch NPT water inlet and outlet
Cons
- Requires four dedicated 40A breakers and four 8 AWG wire runs
- Weighs 34 pounds, heavier than many competing models
Good fit if
- You have electrical panel capacity for four 40A breakers.
- You want a digital touchscreen interface with a child lock.
- You require water temperatures adjustable up to 140°F.
Skip if
- You cannot support four separate 40-amp circuit breakers.
- You prefer a lighter unit than this 34-pound chassis.
Verdict: VEVOR 36kW Touchscreen Electric Tankless Water Heater delivers 240V high-capacity heating with a touch interface and aluminum isolation. It is a solid choice if your electrical infrastructure can supply its four-breaker wiring requirement.
Atmor 36kW 7.03 GPM Tankless Water Heater
Best for: homes needing high multi-bath flow rates
- Wattage
- 36 kW (what this guide is about)
- Fuel Type
- Electric
- Flow Rate
- 7.03 GPM
- Temperature Control
- 90°F–125°F, 1°F increments
- Certification
- cETL
- Dimensions
- 23.2 x 4.49 x 14.3 inches
This 36 kW electric tankless water heater delivers up to 7.03 GPM for whole-home demand. It features a 0.99 UEF rating and allows digital temperature adjustments from 90°F to 125°F in 1°F increments. You can run up to four to five bathrooms in warm climates or three in cooler regions. It requires four 40-amp double pole breakers and connects via standard 3/4-inch NPT fittings.
Pros
- Delivers up to 7.03 GPM flow rate
- 0.99 Uniform Energy Factor (UEF) rating
- Digital temperature settings from 90°F to 125°F in 1°F increments
- Stainless steel internal components with dual over-temperature cutoff
Cons
- Maximum output temperature stops at 125°F
- Requires four 40-amp double pole breakers and four 8/2 AWG wire runs
Good fit if
- You need up to 7.03 GPM to supply multiple fixtures simultaneously.
- You want digital control with exact 1°F temperature adjustments.
- You have panel capacity for four dedicated 40-amp double pole breakers.
Skip if
- You require water temperatures higher than 125°F.
- You cannot accommodate four double pole breakers and four 8/2 AWG wire lines.
Verdict: Atmor 36kW 7.03 GPM Tankless Water Heater delivers high flow rates and 0.99 UEF efficiency for homes with substantial simultaneous hot water demands. Its heavy electrical requirements are balanced by precise 1°F controls and durable stainless steel internals.
Rheem 36 kW Electric Tankless Water Heater
Best for: high-demand 240V homes wanting manual external control
- Wattage
- 36 kW (what this guide is about)
- Fuel Type
- Electric
- Voltage
- 240V
- Temperature Control
- Ext Adj Temp Ctrl
- Dimensions
- Bot 3/4 in. Npt Con
- Weight
- 24.4 pounds
This Rheem unit is a 36 kW electric tankless water heater designed for 240-volt electrical setups. It features external adjustable temperature controls on the front interface and utilizes bottom-mounted 3/4-inch NPT connections for plumbing integration. Weighing 24.4 pounds, it suits your home if you need high-power electric heating from a dedicated 240V source with manual, direct temperature management.
Pros
- 36 kW heating output at 240 volts
- External adjustable temperature control
- Standard bottom 3/4-inch NPT plumbing connections
- Compact weight at 24.4 pounds
Cons
- No wireless connectivity or mobile controls listed
- Requires high-capacity 240V electrical infrastructure
- Flow rate in gallons per minute not specified in data
Good fit if
- You need a 36 kW electric water heater operating on 240 volts.
- You prefer direct on-unit external temperature adjustment.
- You have plumbing set up for bottom-oriented 3/4-inch NPT connections.
Skip if
- You need smart home integration or remote app adjustment.
- You lack electrical capacity for a 36 kW, 240V appliance.
Verdict: Rheem 36 kW Electric Tankless Water Heater delivers 36 kW of on-demand heating at 240 volts with standard bottom 3/4-inch NPT connections. It is a solid pick if you prioritize straightforward dial-based temperature adjustments over digital wireless features.
MRNIU 36 kW Electric Tankless Water Heater
Best for: compact whole-house 36 kW electric heating
- Wattage
- 36 kW (what this guide is about)
- Fuel Type
- Electric
- Voltage
- 240 V
- Dimensions
- 18 x 17.1 x 17.1 inches
- Use
- Whole House
- Weight
- 18.3 pounds
The MRNIU 36 kW Electric Tankless Water Heater provides on-demand heating for whole-house use. Operating at 240 volts, this 36,000-watt electric unit mounts directly to your wall to preserve floor space. It includes an integrated LED temperature display, automatic shut-off, and built-in overheat protection. At 18.3 pounds and measuring 18 by 17.1 by 17.1 inches, it gives you full 36 kW electric capacity in a compact, tankless form factor.
Pros
- Full 36 kW heating output at 240 volts
- Built-in LED temperature display
- Safety shut-off with overheat protection
- Lightweight 18.3-pound wall-mount chassis
Cons
- Gallons-per-minute flow ratings not specified in product data
- 17.1-inch depth extends farther from wall than slim-profile units
Good fit if
- You need a 36 kW electric unit with a front-facing LED temperature display.
- You want a lightweight 18.3-pound wall-mounted heater for whole-house setups.
Skip if
- You require verified GPM flow-rate specifications prior to purchase.
- You need an ultra-thin wall unit with under 17 inches of depth.
Verdict: MRNIU 36 kW Electric Tankless Water Heater delivers 36,000 watts of on-demand power with an integrated LED screen and automated safety shut-off. Its 18.3-pound frame mounts cleanly while meeting high-draw 240V whole-house heating needs.
Rheem 36 kW 6 GPM Electric Tankless Water Heater
Best for: homes needing 6 GPM electric water heating
- Wattage
- 36 kW (what this guide is about)
- Fuel Type
- Electric
- Flow Rate
- 6 GPM
- Dimensions
- 18.3 x 21.6 x 21.6 inches
- Weight
- 19 pounds
View on Amazon: Rheem 36 kW 6 GPM Electric Tankless Water Heater
This electric tankless water heater delivers 36 kW of heating power and supplies a flow rate of up to 6 GPM. Its self-modulating technology adjusts energy use, while the gray enclosure weighs 19 pounds and measures 18.3 by 21.6 by 21.6 inches. It suits you if you need high-capacity electric water heating from a tested, certified refurbished unit packaged with all relevant accessories.
Pros
- Delivers 36 kW electric heating capacity
- Provides a 6 GPM flow rate
- Features self-modulating power regulation
- Weighs 19 pounds for easier handling
Cons
- Refurbished model that may arrive in a generic box
- Requires 21.6 inches of depth and width clearance
Good fit if
- You want a 36 kW electric system capable of up to 6 GPM.
- You accept a certified refurbished model inspected to work like new.
- You have wall space to accommodate a 21.6 by 21.6 inch unit.
Skip if
- You require a brand-new factory unit rather than a refurbished model.
- You need a continuous flow rate exceeding 6 GPM.
Verdict: Rheem 36 kW 6 GPM Electric Tankless Water Heater pairs a 36 kW heating profile with a 6 GPM flow rate in a tested refurbished design. It offers self-modulating electric performance in a 19-pound gray chassis.
EcoSmart 36 kW Electric Tankless Water Heater
Best for: Compact installations with strong electrical capacity
- Wattage
- 36 kW (what this guide is about)
- Fuel Type
- Electric
- Voltage
- 240 V
- Dimensions
- 17 x 21 x 3.6 inches
- Weight
- 18.4 pounds
View on Amazon: EcoSmart 36 kW Electric Tankless Water Heater
The EcoSmart ECO 36 delivers 36 kW of electric heating power at 240 volts. It measures 17 x 21 x 3.6 inches and weighs 18.4 pounds. The unit features a digital output temperature display and uses 3/4 inch NPT pipe fittings. You need four 40-amp breakers for installation. This compact design suits homes where space is limited but high flow rates are required.
Pros
- 36 kW electric heating capacity
- Digital output temperature display
- Compact dimensions of 17 x 21 x 3.6 inches
- 99.8-percent energy efficiency rating
Cons
- Requires four 40-amp breakers for operation
- No WiFi connectivity mentioned in specifications
- Lacks remote control capability
Good fit if
- You need a compact unit for tight spaces
- You have the electrical capacity for four 40-amp breakers
- You want precise temperature control via digital display
Skip if
- You require WiFi smart home integration
- Your electrical panel cannot support four 40-amp breakers
- You prefer gas-powered heating solutions
Verdict: EcoSmart ECO 36 Electric Tankless Heater provides reliable 36 kW heating in a small footprint. It fits well for users who can handle the four 40-amp breaker requirement and value a digital temperature display.
Eemax 36 kW Stainless Steel Tankless Water Heater
Best for: US-made 36 kW stainless steel electric heating
- Wattage
- 36 kW (what this guide is about)
- Fuel Type
- Electric
- Voltage
- 240 V
- Dimensions
- 4.5 x 21 x 18 inches
- Weight
- 17.4 pounds
View on Amazon: Eemax 36 kW Stainless Steel Tankless Water Heater
This Eemax unit is an electric tankless water heater running on a 240 V power supply to deliver 36 kW of heating output. It features a stainless steel casing, weighs 17.4 pounds, and has dimensions of 4.5 by 21 by 18 inches. This setup suits you if you require a 36 kW electric heater manufactured in the United States designed for endless hot water delivery.
Pros
- Delivers 36 kW heating output at 240 V
- Stainless steel exterior construction
- Lightweight 17.4-pound total weight
- Manufactured in the United States
Cons
- No flow rate or GPM rating specified in product data
- No digital display or Wi-Fi control listed in specifications
Good fit if
- You need a 36 kW, 240 V electric tankless water heating system.
- You prioritize equipment manufactured in the United States.
- You want a stainless steel exterior with a depth of 4.5 inches.
Skip if
- You need documented flow rate specifications in gallons per minute before buying.
- You want built-in smart controls or Wi-Fi functionality.
Verdict: Eemax 36 kW Stainless Steel Tankless Water Heater delivers 36 kW of electric heating output at 240 V in a 17.4-pound package. Manufactured in the United States, it provides endless hot water with a stainless steel finish.
MIZUDO 36 kW Electric Tankless Water Heater
Best for: Multi-fixture homes with high electrical service capacity
- Wattage
- 36 kW (what this guide is about)
- Fuel Type
- Electric
- Flow Rate
- 8.7 GPM
- Voltage
- 240V
- Temperature Control
- 86–140°F, ±1°F
- Dimensions
- 17.1 x 18.5 x 3.7 inches
The MIZUDO 36 kW Electric Tankless Water Heater is a whole-house unit designed to run up to 5 to 6 fixtures simultaneously. It draws 240V to deliver up to 8.7 GPM at a 77°F inlet temperature, dropping to 5.1 GPM at 57°F. With an LED touch display offering temperature control from 86°F to 140°F, it suits you if your electrical panel can supply four 40-amp double-pole breakers.
Pros
- Delivers up to 8.7 GPM with 98% heating efficiency
- LED touch display with 86°F to 140°F adjustment within ±1°F
- Compact 17.1 x 18.5 x 3.7-inch wall-mountable frame
- Built-in leakage, dry-heating, and over-temperature safety protections
Cons
- Requires four 40A double-pole breakers and four 8 AWG wire runs
- Output drops to 5.1 GPM when inlet water temperature reaches 57°F
Good fit if
- You need to supply hot water for 5 to 6 fixtures at the same time.
- You have electrical panel capacity for four 40-amp two-pole breakers and four 8 AWG lines.
- You want digital temperature adjustments ranging from 86°F to 140°F.
Skip if
- You cannot accommodate four dedicated 40A breakers in your home electrical panel.
- You live in a cold climate where 57°F inlet temperatures yield only 5.1 GPM and you need higher flow.
Verdict: MIZUDO 36 kW Electric Tankless Water Heater delivers high flow rates and tight ±1°F temperature management for multi-fixture homes. It requires substantial electrical infrastructure, needing four dedicated 40A circuits.
Eemax 36 kW Compact Tankless Water Heater
Best for: shallow utility spaces needing 36 kW heating
- Wattage
- 36 kW (what this guide is about)
- Fuel Type
- Electric
- Dimensions
- 17.5 × 21 × 3.75 inches
This Eemax electric tankless water heater delivers on-demand hot water using 36 kW of power. Its self-modulating technology adjusts energy draw to match your exact hot water demand. With dimensions of 17.5 inches long, 21 inches wide, and 3.75 inches high, this compact unit fits into tight utility spaces. It suits you if you need a high-power electric setup to supply hot water without a storage tank.
Pros
- 36 kW power rating for continuous hot water delivery
- Self-modulating technology adjusts energy draw to match demand
- Slim 3.75-inch depth fits shallow mounting locations
- Compact 21-inch by 17.5-inch footprint saves wall space
Cons
- Flow rate capacity in GPM is not specified in the data
- No external display or temperature controls listed
- Requires substantial 36 kW electric service capacity
Good fit if
- You need a 36 kW electric unit with self-modulating power regulation.
- You require a shallow unit under 4 inches deep for space-constrained walls.
- You want continuous on-demand hot water without keeping a tank.
Skip if
- You require confirmed flow rate specifications before buying.
- You use gas instead of high-capacity electric hookups.
- You want built-in digital screens or Wi-Fi monitoring features.
Verdict: Eemax 36 kW Compact Tankless Water Heater provides self-modulating electric heating inside a slim 3.75-inch-deep profile. It delivers continuous hot water if your home supports a 36 kW electrical load.
Stiebel Eltron Tempra 36 Trend Electric
Best for: homes with 300-amp service needing bundled valves
- Wattage
- 36 kW (what this guide is about)
- Fuel Type
- Electric
- Voltage
- 240 V
- Temperature Control
- 68° to 140°F
This Stiebel Eltron unit is an electric tankless water heater bundled with 3/4-inch service valves. It delivers 36 kW of on-demand heating on a 240-volt electrical supply, regulating water temperatures from 68°F to 140°F via auto-modulation. A digital display lets you monitor output settings. It suits you if you have a 300-amp electrical service panel and want a silent, vent-free whole-house heating setup that includes installation valves.
Pros
- Includes 3/4-inch lead-free tankless service valves
- Solid copper heating system with auto-modulation
- Digital display with output range from 68° to 140°F
- Requires no venting and operates silently
Cons
- Requires high 300 A electrical service
- No wireless or smart connectivity features listed
Good fit if
- You have at least 300 A of electrical service available.
- You want a 36 kW unit bundled with 3/4-inch service valves.
- You need an adjustable target temperature between 68° and 140°F.
Skip if
- You have an electrical panel with less than 300 A capacity.
- You want app-based control or Wi-Fi monitoring.
Verdict: Stiebel Eltron Tempra 36 Trend with Service Valves pairs a 36 kW auto-modulating copper heating system with dedicated maintenance valves. It delivers silent, reliable high-output heating if your home meets the 300 A electrical service requirement.
Atmor 36 kW 6.2 GPM Electric Tankless Water Heater
Best for: high-demand homes with sufficient electrical panel capacity
- Wattage
- 36 kW (what this guide is about)
- Fuel Type
- Electric
- Flow Rate
- 6.2 GPM
- Voltage
- 240V
View on Amazon: Atmor 36 kW 6.2 GPM Electric Tankless Water Heater
This Atmor electric tankless water heater delivers up to 6.2 GPM at 36 kW on a 240V electrical supply. It requires four 40-amp double-pole breakers and four 8/2 AWG wire runs. You get continuous hot water without venting or gas lines. This high-capacity unit suits whole-house residential setups or light commercial spaces needing dependable demand heating without standby heat loss.
Pros
- Delivers up to 6.2 GPM flow rate
- Requires no gas line or venting infrastructure
- Includes 7-year leakage and 2-year parts warranty coverage
- Rated for residential and light commercial use
Cons
- Requires four 40-amp double-pole breakers
- Requires four separate 8/2 AWG wire runs
Good fit if
- You need up to 6.2 GPM of continuous hot water.
- You have panel capacity for four 40-amp double-pole breakers.
- You want an electric unit that avoids venting and gas lines.
Skip if
- You lack electrical panel space for four double-pole breakers.
- You cannot accommodate four 8/2 AWG wire runs.
Verdict: Atmor 36 kW 6.2 GPM Electric Tankless Water Heater provides high-volume continuous hot water for residential or light commercial applications. It relies on a heavy 240V electrical configuration requiring four dedicated breaker circuits.
RDYYKUKHG 36 kW Under Sink Water Heater
Best for: high-demand under-sink installations with heavy electrical capacity
- Wattage
- 36 kW (what this guide is about)
- Fuel Type
- Electric
- Voltage
- 240V
- Temperature Control
- 30–60°C
- Dimensions
- 12 x 8 x 8 inches
- Use
- Under Sink
This RDYYKUKHG unit delivers 36 kW of electric heating in a compact 12 by 8 by 8-inch enclosure designed for under-sink placement. It operates on 240 volts and supplies water between 30 and 60°C via a die-cast aluminum heating element. If you need high-power heating in tight quarters like a kitchen, office, or bathroom, its small footprint fits under counters while requiring four 40A circuit breakers.
Pros
- Compact 12 x 8 x 8-inch dimensions fit under sink locations
- Die-cast aluminum element isolates water from electrical circuits
- Standard 3/4-inch NPT inlet and outlet connections
- Touch-screen interface includes long-press security lock
Cons
- Heavy 80.2-pound weight for a compact enclosure
- Requires four 40A breakers and eight-gauge wiring
- No flow rate in gallons per minute specified
Good fit if
- You need a 36 kW heater small enough to mount under a sink or counter.
- You have electrical service capable of running four dedicated 40A breakers.
- You want an adjustable output temperature ranging from 30 to 60°C.
Skip if
- You cannot accommodate an 80.2-pound unit on your mounting surface.
- Your electrical panel lacks space for four 40A breakers.
Verdict: RDYYKUKHG 36 kW Under Sink Water Heater packs 36 kW of power into a 12-inch-tall frame suitable for under-sink installation. It provides stable 30 to 60°C output if your electrical panel can support its four 40A circuit requirement.
Specifications side by side
| Spec | Stiebel Eltron Tempra 36 Trend Tankless Water Heater | WINTEMP 36kW Electric Tankless Water Heater | WINTEMP 36 kW WiFi Tankless Water Heater | VEVOR 36kW Touchscreen Electric Tankless Water Heater | Atmor 36kW 7.03 GPM Tankless Water Heater | Rheem 36 kW Electric Tankless Water Heater | MRNIU 36 kW Electric Tankless Water Heater | Rheem 36 kW 6 GPM Electric Tankless Water Heater | EcoSmart 36 kW Electric Tankless Water Heater | Eemax 36 kW Stainless Steel Tankless Water Heater | MIZUDO 36 kW Electric Tankless Water Heater | Eemax 36 kW Compact Tankless Water Heater | Stiebel Eltron Tempra 36 Trend Electric | Atmor 36 kW 6.2 GPM Electric Tankless Water Heater | RDYYKUKHG 36 kW Under Sink Water Heater |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Fuel Type | Electric | Electric | Electric | Electric | Electric | Electric | Electric | Electric | Electric | Electric | Electric | not specified | Electric | Electric | Electric |
| Flow Rate | not specified | 8.7 GPM | 8.7 GPM | not specified | 7.03 GPM | not specified | not specified | 6 GPM | not specified | not specified | 8.7 GPM | not specified | not specified | 6.2 GPM | not specified |
| Wattage | 36 kW | 36 kW | 36 kW | 36KW | 36kW | 36kW | 36,000 W | 36 kW | 36 kW | 36 kW | 36kW | not specified | 36 kW | 36 kW | 36kW |
| Voltage | 240 V | 240 V | 240V | 240V | not specified | 240V | 240 V | not specified | 240 V | 240 V | 240V | not specified | 240 V | 240V | 240V |
| Temperature Control | 68° to 140°F | not specified | 86°F to 140°F | 30-60°C / 86-140°F | 90°F–125°F, 1°F increments | Ext Adj Temp Ctrl | not specified | not specified | not specified | not specified | 86–140°F, ±1°F | not specified | 68° to 140°F | not specified | 30–60°C |
| Certification | not specified | ETL | ETL | not specified | cETL | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified |
| Dimensions | 14.5 x 16.6 x 4.63 in | 21.5" H × 13.7" W × 5.2" D | 19.4" x 13.7" x 4.6" | 13.7 x 13.7 x 5.31 inches | 23.2 x 4.49 x 14.3 inches | Bot 3/4 in. Npt Con | 18 x 17.1 x 17.1 inches | 18.3 x 21.6 x 21.6 inches | 17 x 21 x 3.6 inches | 4.5 x 21 x 18 inches | 17.1 x 18.5 x 3.7 inches | not specified | not specified | not specified | 12 x 8 x 8 inches |
| Use | Whole House | Whole House | Whole House | not specified | not specified | not specified | Whole House | not specified | not specified | not specified | Whole House, Under Sink | not specified | not specified | not specified | Under Sink |
| Features | not specified | WiFi | WiFi | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified |
| Weight | 19 pounds | 36.1 pounds | 38 pounds | 34 pounds | 18.2 pounds | 24.4 pounds | 18.3 pounds | 19 pounds | 18.4 pounds | 17.4 pounds | not specified | not specified | not specified | not specified | 80.2 pounds |
| Size | 36 (kW) | 36kW | not specified | 36KW | 7.03 GPM | not specified | not specified | not specified | not specified | not specified | L-36 | 36Kw | not specified | 36 kW | Compact |
| Color | White | Gray | Gray | Black | Gray | Silver | White | Gray | White | Stainless Steel | Whitish | Blue | White | 36kW | Silver |
| Model | 36 Trend | WN36 | WM36V | JN36 | AT-36N-XTP | RTEX-36 | Mrniu36 | RTEX-36 | ECO 36 | HA036240 | 36kW | EEM24036 | not specified | AT-912-36TP | IFN-41992 |
Is 36 kW Worth the Electrical Upgrade?
A 36 kW rating provides high-flow hot water, typically reaching 6 to 8.7 GPM depending on inlet temperature. This output supports whole-house use or simultaneous multi-bathroom demand. However, it requires significant electrical infrastructure. Most models need four dedicated 40-amp breakers or 150 to 300 amps of service. If your panel cannot handle this load, the unit will not function correctly. You must verify your home’s capacity before installing.
Worth it if
- You need high flow rates for multiple bathrooms
- Your electrical panel supports 150 to 300 amps
- You want whole-house hot water on demand
Skip it if
- You only need hot water for a single sink
- Your electrical service is less than 100 amps
- You cannot install four dedicated 40-amp breakers
If you also plan home gym equipment alongside utility upgrades, you can compare specs for the best water rowers.
How We Picked 36 kW Heaters
We identified these units by scanning Amazon listings for the 36 kW wattage specification. This power level ensures whole-house capacity for most homes. We verified the data directly from the published feature lists and titles. Only one variant per product family appears in this guide. All details come strictly from the specifications provided by the manufacturers. We do not handle or test the hardware ourselves. You can trust these numbers as they appear on the official product pages. We avoid guessing or inferring capabilities beyond what is explicitly stated in the technical data. This approach keeps the information accurate and consistent. We focus on the hard specs that matter for your installation. The selection process relies entirely on the published data available online. This ensures you get reliable information for your buying decision.
How to choose the right 36 kW unit
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Match voltage to your panel
All 36 kW models in this guide require 240V power. You must verify your electrical panel can supply the necessary amperage before purchasing. Most units demand four dedicated breakers or a 150 to 300-amp service. The Stiebel Eltron Tempra 36 Trend specifically notes a need for 300 A panels. If your home lacks this capacity, you cannot safely install these high-output heaters. Check your main breaker box rating first to avoid costly electrical upgrades.
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Select based on flow needs
Flow rate determines how many fixtures you can run simultaneously. Higher GPM ratings support whole-house use or multiple bathrooms. The WINTEMP WM36V delivers a high 8.7 GPM output, suitable for high-demand households. The Atmor AT-36N-XTP offers 7.03 GPM for substantial simultaneous hot water needs. If you only need a single sink, a lower flow unit may suffice. Compare the GPM specs to your peak usage times to ensure you never run out of hot water during busy mornings.
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Consider installation location
Physical dimensions dictate where you can mount the heater. The EcoSmart ECO 36 is only 3.6 inches deep, making it ideal for tight utility spaces. The RDYYKUKHG model is designed specifically for under-sink installations with a compact 12-inch height. Measure your available space carefully, including clearance for wiring and maintenance access. Some units are taller but narrower, while others are wider but shallower. Ensure the chosen model fits your designated area without obstructing other utilities or access panels.
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Choose control interface type
Controls affect how you adjust temperature. The WINTEMP WN36 includes WiFi for mobile app adjustments and monitoring. The VEVOR JN36 features a touch interface for direct manual input. The Rheem RTEX-36 uses standard dial-based adjustments for straightforward operation. The MRNIU model integrates an LED screen for clear status reading. Select the interface that matches your preference for digital convenience versus mechanical simplicity. Digital controls offer remote access, while dials provide reliable manual override without relying on electronics.
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Check internal material durability
Internal construction impacts longevity and resistance to corrosion. The Atmor AT-36N-XTP features durable stainless steel internals for extended service life. The Stiebel Eltron Tempra 36 Trend with Service Valves uses an auto-modulating copper heating system. Stainless steel resists mineral buildup better than some copper alloys in hard water areas. Copper offers efficient heat transfer but may require more maintenance in certain water conditions. Review the material specs to align with your local water quality and desired maintenance intervals.
Frequently asked questions
Which 36 kW tankless water heater is the best overall choice?
The Stiebel Eltron Tempra 36 Trend is the top pick. It delivers 36 kW of modulated electric heating across a broad temperature range. This model provides whole-house capacity without venting, provided your home supports 300 A service. It balances performance with a manageable 19-pound weight for installation.
What is the best 36 kW unit for smart home integration?
The WINTEMP WN36 is the best option for smart control. It includes WiFi capabilities for mobile app adjustments and monitoring. This unit suits high-demand households with multi-bathroom setups. It requires a 300A electrical service to support its high flow capacity and digital features effectively.
Which 36 kW heater offers the highest flow rate?
The WINTEMP WM36V provides the highest flow rate at 8.7 GPM. It pairs this output with app-based power tracking and automatic temperature stabilization. This model is ideal for homes wanting high flow and smart monitoring. Note that it requires a demanding 150-amp electrical setup.
Is there a 36 kW tankless heater suitable for under-sink installation?
The RDYYKUKHG IFN-41992 is designed for under-sink use. It packs 36 kW of power into a 12-inch-tall frame. This unit provides stable output between 30 and 60°C. It requires significant electrical infrastructure, specifically four 40A circuits, to operate safely in a compact space.
Which 36 kW model is the most compact for tight spaces?
The EcoSmart ECO 36 is the most compact option. It measures only 3.6 inches in depth, fitting easily into tight utility spaces. It provides reliable 36 kW heating with a digital temperature display. You must ensure your electrical panel can handle its four 40-amp breaker requirement.
What is the best 36 kW heater for stainless steel durability?
The Eemax HA036240 features a stainless steel construction. It delivers 36 kW of electric heating at 240 V in a lightweight 17.4-pound package. This US-made unit provides endless hot water with a durable stainless steel finish. It is a solid choice for longevity and corrosion resistance.
Which 36 kW heater uses a touchscreen interface?
The VEVOR JN36 includes a touchscreen interface for control. It delivers 240V high-capacity heating with aluminum isolation for safety. This model is ideal for homes with high-amperage electrical panels. It requires four-breaker wiring to support its power demands and digital operation.
Which 36 kW unit is best for manual temperature control?
The Rheem RTEX-36 is best for manual adjustments. It offers straightforward dial-based temperature control rather than digital wireless features. This model delivers 36 kW of on-demand heating at 240 volts. It uses standard bottom 3/4-inch NPT connections for easy plumbing integration.