MIZUDO Natural Gas Tankless Water Heater or MIZUDO Tankless Water Heater Electric? Which MIZUDO Model to Buy
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You are comparing the mizudo natural gas tankless water heater vs tankless water heater electric models from the same brand. Both units deliver whole-house hot water with precise temperature control. The main difference lies in their energy source and installation needs. One uses natural gas with a high BTU rating, while the other relies on 240V electricity. Your choice depends on your home’s existing infrastructure and available space.
Key differences
| Aspect | MIZUDO 8.1 GPM Outdoor Natural Gas Tankless Heater | MIZUDO 36 kW Electric Tankless Water Heater |
|---|---|---|
| Fuel Type | Natural Gas | Electric |
| Voltage | 120V | 240V |
| Flow Rate | 8.1 GPM | 8.7 GPM |
| Installation Location | Outdoor | Indoor/Outdoor |
| Dimensions | 26.2 x 17.1 x 7.1 inches | 17.1 x 18.5 x 3.7 inches |
Which one should you choose?
Choose MIZUDO 8.1 GPM Outdoor Natural Gas Tankless Heater if
- You have access to a natural gas line and need a unit designed for outdoor mounting.
- You want to support simultaneous hot water use across multiple bathrooms with high BTU output.
- You prefer a unit with a built-in remote panel for temperature adjustment.
Choose MIZUDO 36 kW Electric Tankless Water Heater if
- You need a compact unit that fits in tight indoor spaces like closets or under sinks.
- You have an electrical panel capable of supporting four 40A breakers and 8 AWG wiring.
- You want faster heating times with a slim profile that saves significant wall space.
Verdict: Choose the natural gas model if you have outdoor space and a gas line, as it handles high-demand households effectively. Pick the electric model if you are short on space and have the necessary electrical capacity for a compact, whole-house solution.
Gas vs Electric MIZUDO Heaters
Fuel type
Product A uses natural gas, requiring a gas line connection and outdoor installation. It operates on a standard 120V power supply for its control systems and fan. Product B is an electric unit that requires a 240V electrical circuit. This difference dictates your entire installation infrastructure. You must have the correct fuel source available at your installation site. One model needs gas piping and venting, while the other needs high-amperage electrical wiring. Choose based on which utility is already present or easiest to install in your home.
Flow rate
Product B offers a higher maximum flow rate of 8.7 GPM at a 77°F inlet temperature. Product A provides up to 8.1 GPM. Both units support whole-house hot water demands. However, actual flow depends on your inlet water temperature. Product B’s flow drops to 5.1 GPM at 57°F inlet. Product A maintains precise temperature control within ±1°F. If you need the highest possible flow in mild climates, Product B has a slight advantage. In colder climates, both units will see reduced flow rates due to the temperature rise required.
Temperature range
Product A allows you to adjust the water temperature up to 167°F. This high setting is useful for deep soaking tubs or heavy-duty laundry cycles. Product B has a maximum adjustable temperature of 140°F. Both units offer precise control within ±1°F of your set point. Product A starts with a default setting of 107°F. Product B allows settings from 86°F to 140°F. If you need very hot water for specific sanitation needs or large tubs, Product A provides a wider range. For standard showers and sinks, both are sufficient.
Dimensions
Product B is significantly more compact in height and depth. It measures 17.1 inches wide, 18.5 inches high, and 3.7 inches deep. Product A is taller and deeper, measuring 26.2 inches high, 17.1 inches wide, and 7.1 inches deep. Product B’s slim profile allows it to fit under sinks or in tight corners. Product A is designed for outdoor mounting and is larger to accommodate its gas components. If space is limited, Product B saves more room. Its compact design fits easily into closets or small utility rooms.
Installation location
Product A is certified for outdoor installation by CSA. It is designed to keep indoor space uncluttered and uses a bottom-mounted fan to prevent exhaust backflow. It is not recommended for elevations above 2,000 feet. Product B is designed for indoor use, such as under sinks or in utility rooms. It does not require gas venting. You must verify panel capacity for Product B. Product A requires professional installation for gas connections. Choose Product A for outdoor mounting. Choose Product B for indoor spaces where gas lines are unavailable.
Warranty
Product A includes a 2-year full unit warranty and 5-year heat exchanger coverage. It also provides 24/7 customer support. Product B mentions long-term return and exchange services with professional technical support. The specific duration of Product B’s warranty is not listed in the provided data. Product A offers clear, extended protection for its heat exchanger. This is a critical component for gas units. If warranty length is a priority, Product A provides more specific coverage terms. You should check Product B’s official documentation for exact warranty periods.
Which MIZUDO heater fits your home
Homeowners with existing gas lines
This natural gas model delivers 180,000 BTU and up to 8.1 GPM. It supports simultaneous use across multiple bathrooms and kitchens. The unit is designed for outdoor installation and features precise temperature control within ±1°F. It includes a 2-year full warranty and 5-year heat exchanger coverage for long-term reliability.
Users needing compact indoor units
This electric heater measures only 3.7 inches deep, fitting easily under sinks or in closets. It requires 240V power and three-quarter inch NPT connections. The unit heats water in 3 seconds and offers precise control between 86°F and 140°F. It includes safety protections against leakage and dry-heating for secure indoor operation.
Budget-conscious buyers seeking efficiency
The electric model boasts 98% efficiency and claims to cut energy costs significantly. It provides up to 8.7 GPM at a 77°F inlet temperature. The smart chip adjusts power 20,000 times per second to maintain steady water temperature. This high efficiency makes it a practical choice for reducing ongoing utility expenses.
The products compared
MIZUDO 8.1 GPM Outdoor Natural Gas Tankless Heater
Best for: Outdoor whole-house hot water with high flow
- Fuel Type
- Natural Gas
- Flow Rate
- Up to 8.1 GPM
- BTU
- 180,000 BTU
- Installation Location
- Outdoor
- Voltage
- 120V
- Temperature Control
- 95–167°F, ±1°F
View on Amazon: MIZUDO 8.1 GPM Outdoor Natural Gas Tankless Heater Affiliate link
This MIZUDO unit delivers up to 8.1 GPM of hot water using 180,000 BTU of natural gas. It features precise ±1°F temperature control and a low 0.53 GPM activation flow. The compact design fits outdoor spaces, measuring 26.2 by 17.1 inches. It includes a large LED display and remote panel for easy adjustments. This model suits busy households needing simultaneous hot water for multiple bathrooms and kitchen fixtures.
Pros
- High 8.1 GPM flow rate for whole-house demand
- Precise ±1°F temperature stability with fast 13-second heating
- Low 0.53 GPM activation saves energy at low flow
- CSA certified for safe outdoor installation
- Intuitive touch control with large LED display
Cons
- Limited to outdoor installation only
- Not recommended for elevations above 2,000 feet
- Standard 2-year full unit warranty is shorter than some competitors
Good fit if
- You need high flow for 2–3 bathrooms running at once
- You want precise temperature control for soaking tubs
- You have outdoor space for installation
Skip if
- You require indoor installation
- You live above 2,000 feet elevation
- You need propane fuel instead of natural gas
Verdict: MIZUDO 180k BTU Natural Gas Outdoor Heater provides robust whole-house hot water with precise temperature control. It is the right choice for outdoor installations where high flow and stability matter most.
MIZUDO 36 kW Electric Tankless Water Heater
Best for: Whole-house electric heating with precise temp control
- Fuel Type
- Electric
- Flow Rate
- Up to 8.7 GPM
- Wattage
- 36kW
- Voltage
- 240V
- Temperature Control
- 86–140°F, ±1°F
- Dimensions
- 18.5 x 17.1 x 3.7 in
View on Amazon: MIZUDO 36 kW Electric Tankless Water Heater Affiliate link
This MIZUDO unit is a 36kW, 240V electric tankless water heater designed for whole-house use. It delivers up to 8.7 GPM at a 77°F inlet temperature. The device features an LED touch display for precise temperature control between 86°F and 140°F. Its compact dimensions of 17.1 x 18.5 x 3.7 inches allow for easy wall mounting in tight spaces. You need four 40A breakers and 8 AWG wiring for installation.
Pros
- Delivers up to 8.7 GPM at 77°F inlet
- Precise temperature control with ±1°F accuracy
- Compact 17.1 x 18.5 x 3.7 inch design
- LED touch display for easy adjustment
Cons
- Requires four 40A two-pole breakers
- Needs 8 AWG wire sets
- Electric model lacks BTU rating
Good fit if
- You have the electrical capacity for 4 x 40A breakers
- You need a compact unit for small spaces
- You prefer precise digital temperature control
Skip if
- You only have a standard 200A electrical panel without capacity for 160A
- You are looking for a natural gas model
- You cannot install 8 AWG wiring
Verdict: MIZUDO 36kW Electric Tankless Water Heater fits homes with sufficient electrical capacity that need a compact, whole-house solution. It offers steady temperature control for multiple fixtures.
Specifications side by side
| Spec | MIZUDO 8.1 GPM Outdoor Natural Gas Tankless Heater | MIZUDO 36 kW Electric Tankless Water Heater |
|---|---|---|
| Fuel Type | Natural Gas | Electric |
| Flow Rate | Up to 8.1 GPM | Up to 8.7 GPM |
| BTU | 180,000 BTU | not stated |
| Wattage | not stated | 36kW |
| Installation Location | Outdoor | not stated |
| Voltage | 120V | 240V |
| Temperature Control | 95–167°F, ±1°F | 86–140°F, ±1°F |
| Certification | CSA | not stated |
| Dimensions | 26.2 x 17.1 x 7.1 inches | 18.5 x 17.1 x 3.7 in |
| Use | Whole House | Whole House, Under Sink |
| Size | Natural Gas, 8.1 GPM, 180,000 BTU, Indoor | L-36 |
| Color | White 8.1NG | Whitish |
| Model | HS180A0W-NG | 36kW |
Frequently asked questions
Can I install the MIZUDO gas heater indoors?
No. The MIZUDO 8.1 GPM Natural Gas model is designed for outdoor use only. Its specifications list the installation location as outdoor. You should not place this unit inside your home due to ventilation and safety requirements. Choose the electric model if you need an indoor installation option.
What is the maximum flow rate for the gas model?
The gas model provides up to 8.1 gallons per minute. This high flow rate supports whole-house hot water needs. It allows you to run multiple fixtures simultaneously. The electric model does not list a GPM rating in the provided data, so the gas unit is the clear choice for high demand.
Does the electric heater require a 240V connection?
Yes. The MIZUDO 36 kW Electric model requires a 240V electrical supply. This is standard for high-wattage tankless heaters. Ensure your home has the necessary electrical capacity before purchasing. The gas model uses natural gas for heating but still needs standard power for its controls.
Which model is better for a house with multiple bathrooms?
The gas model is better for multiple bathrooms. It delivers 8.1 GPM and 180,000 BTU of heat. This capacity handles simultaneous use in several fixtures. The electric unit is also rated for whole-house use, but the gas model offers higher flow and thermal power for busy households.
How big is the MIZUDO gas water heater?
The gas model measures 17.1 inches wide, 26.2 inches high, and 17.1 inches deep. It has a white finish. You need sufficient outdoor space for these dimensions. The electric unit is slightly shorter at 18.5 inches high but shares the same width and depth.
Is temperature control precise on both models?
Yes. Both models offer precise temperature control. The gas unit maintains stable output for outdoor installations. The electric model also provides steady control for whole-house heating. This feature ensures consistent hot water temperature regardless of which model you choose.