Thermomate 11kW Electric Tankless Water Heater Review (2026): A Spec-Based Look
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This thermomate 11kw electric tankless water review looks at a compact unit for point-of-use applications. The Thermomate ET110 delivers 2.15 GPM at a 35°F temperature rise. It operates on 240V power with an 11kW heating element. The self-modulating technology adjusts energy use based on flow. This ensures stable performance within 1°F of your set temperature. The unit features an alloy metal housing and separate heating elements to reduce scale buildup. It is ETL certified for safety. The compact dimensions allow for easy wall mounting in tight spaces like bathrooms or break rooms.
What stands out
- Delivers 2.15 GPM at a 35°F rise for consistent hot water
- Self-modulating technology maintains temperature within 1°F
- Alloy metal housing reduces scale and corrosion buildup
- Compact 11.8" x 3.13" x 14.8" size fits tight spaces
- ETL certified with overheating and leakage protection
Who it fits
Good fit for
You should consider this unit for single bathroom sinks, office break rooms, or RVs. The 2.15 GPM flow rate suits low-demand fixtures. The 240V/11kW setup requires a 60A breaker, so ensure your electrical panel can handle it. If you need endless hot water for a single faucet without tank storage, this compact design saves floor space. It is ideal for point-of-use installations where space is limited.
Who should skip it
You should skip this model if you need hot water for multiple simultaneous fixtures. The 2.15 GPM flow rate is too low for full showers or bathtubs. You also need a dedicated 60A breaker with two double-pole 30A breakers. If your home lacks this electrical infrastructure, installation will be difficult. This unit is not suitable for whole-house heating or high-flow applications.
Verdict: The Thermomate ET110 is a reliable, space-saving option for low-flow point-of-use applications. Its stable temperature control and compact design make it practical for single fixtures.
Key specs explained
Wattage: 11kW
This power rating determines how much energy the unit uses to heat water. An 11kW element is suitable for single fixtures like a bathroom sink or shower. It provides consistent heat for low to moderate flow rates. Higher wattage units handle more simultaneous demand. You should match this spec to your household's water usage needs to ensure adequate hot water supply.
Voltage: 208~240 Volt
This unit requires a standard 240V electrical circuit, similar to what a dryer uses. It operates within a 208 to 240V range for flexibility. You must have the correct wiring and breaker capacity installed. Standard 120V outlets will not work. Verify your home's electrical panel can support this load before installation to avoid tripping breakers or damage.
Flow Rate: 2.15 GPM at 35°F rise
This indicates the volume of hot water delivered when the temperature increases by 35 degrees Fahrenheit. At 2.15 gallons per minute, it suits a single sink or shower. It may struggle with multiple simultaneous outlets. Check your local inlet water temperature. Colder ground water requires more heating power, potentially reducing the final flow rate compared to this rated specification.
Dimensions: 11.8" W x 3.13" H x 14.8" D
These compact measurements allow installation in tight spaces like under sinks or in closets. The slim profile saves floor space compared to tank heaters. Measure your available area carefully to ensure fit. The small footprint makes it ideal for point-of-use applications. You can mount it on walls to keep floors clear and maintain a tidy appearance in small rooms.
Temperature Control: within 1°F
This precision ensures the output water stays very close to your selected setting. You experience stable temperatures without sudden hot or cold spikes. The self-modulating technology adjusts power based on flow to maintain this consistency. This level of control enhances comfort during showers. It reduces the need to constantly adjust the dial while washing hands or dishes.
Design and Build Quality
The Thermomate ET110 features a gray alloy metal housing. This material choice helps reduce scale, corrosion, and mineral buildup on the heating element. The listing states that the heating element is separated from the water tube. This design significantly lowers maintenance needs by preventing direct contact between the element and the water flow. You get a unit built for longevity in areas with hard water.
Its physical footprint is compact, measuring 11.8 inches wide, 3.13 inches high, and 14.8 inches deep. According to the listing, this wall-mounted size fits into tight spaces. You can install it under sinks or in small utility closets without taking up floor space. The 1/2-inch NPT male ports allow for standard plumbing connections. This layout makes it suitable for point-of-use applications like a bathroom sink or office break room.
The unit operates on 240V power with an 11kW heating element. It requires a 60Amp breaker, specifically two sets of double-pole 30AMP breakers. The listing notes that 12AWG wire is needed for installation. This electrical requirement means you must have adequate panel capacity. The self-modulating technology regulates energy use based on flow rate. You get stable performance within 1°F of your selected temperature. The compact design and specific electrical needs define its practical use in residential settings.
Installation and Daily Operation
Setting up this unit requires specific electrical infrastructure. You need a 208 to 240 volt circuit with a 60 amp breaker. This means installing two double-pole 30 amp breakers. The wiring must use 12AWG gauge wire. The water connections use 1/2 inch NPT male ports. This setup limits the heater to point-of-use locations. It is ideal for a single bathroom sink or a small shower. It is not suitable for whole-house supply.
Once installed, the self-modulating technology manages energy use. The unit detects water flow and temperature continuously. It adjusts power to stay within 1°F of your selected setting. This ensures stable performance without sudden temperature swings. The alloy metal housing and separated heating element reduce scale buildup. This design feature helps maintain efficiency over time with low maintenance needs.
Safety is built into the core functions. The ETL certification confirms it meets standard safety requirements. Overheating protection activates if temperatures get too high. The system also stops heating automatically if it detects no water flow. This prevents dry firing. The compact dimensions of 11.8 inches wide and 14.8 inches deep allow it to fit in tight spaces. You get endless hot water on demand. The unit does not store water, so you do not wait for a tank to refill. Daily use involves turning the tap and receiving immediate heat.
Check electrical capacity first
Before you buy, confirm your electrical panel can support the load. You need two double-pole 30 amp breakers and 12AWG wiring. This unit is not for whole-house use. It suits point-of-use spots like bathroom sinks or office break rooms. Check your water pressure and pipe size. The 1/2 inch NPT ports require compatible fittings. Verify your voltage matches the 208 to 240 volt requirement. Mismatched voltage damages the heater. The compact size fits tight spaces, but you need clearance for maintenance. The alloy housing reduces scale, yet mineral buildup still occurs in hard water areas. You may need a water softener or regular descaling to keep the element clean. Compare this to gas models if you lack the electrical capacity. Electric units are efficient but demand robust circuits. Ensure your home’s wiring is up to code. Improper installation voids safety protections. This heater fits well alongside other electric options for small applications. It offers consistent temperature control within 1°F. Just ensure your infrastructure supports the 46 amp draw. Otherwise, consider a lower wattage model.
Check before you buy
- Verify you have two 30 amp double-pole breakers.
- Confirm 12AWG wiring is installed and ready.
- Ensure voltage is 208 to 240 volts.
- Check if 1/2 inch NPT fittings fit your pipes.
The product at a glance
Thermomate 11kW Electric Tankless Water Heater
Best for: compact bathroom or sink installations
- Fuel Type
- Electric
- Flow Rate
- Up to 2.6GPM
- Wattage
- 11kW
- Voltage
- 208~240 Volt
- Temperature Control
- Within 1°F
- Certification
- ETL Certified
View on Amazon: Thermomate 11kW Electric Tankless Water Heater Affiliate link
The Thermomate 11kW electric tankless water heater delivers on-demand hot water with a flow rate of 2.15 GPM at a 35°F temperature rise. It operates on 208–240V power and maintains temperature within 1°F. Its compact 11.8-inch width and 3.13-inch height allow for wall mounting in tight spaces. This unit is ideal for bathrooms or small sinks where space is limited.
Pros
- Self-modulating technology adjusts energy use based on flow rate
- Alloy metal housing reduces scale and corrosion buildup
- ETL certified with overheating and auto-stop protection
- Maintains temperature within 1°F of selected setting
Cons
- Requires a 60Amp breaker setup (two 30Amp double-pole breakers)
- Flow rate of 2.15 GPM may be low for multiple simultaneous uses
- Limited to point-of-use or low-flow applications
Good fit if
- You need a compact unit for a bathroom or small sink
- You have the electrical capacity for a 60Amp breaker
- You want precise temperature control within 1°F
Skip if
- You require high flow rates for multiple showers
- You cannot install dual 30Amp double-pole breakers
- You prefer gas-powered heating systems
Verdict: Thermomate 11kW Electric Tankless Water Heater is a compact, efficient option for low-flow applications like bathrooms. It suits buyers with adequate electrical infrastructure who value precise temperature stability and space-saving design.
Specifications side by side
| Spec | Thermomate 11kW Electric Tankless Water Heater |
|---|---|
| Fuel Type | Electric |
| Flow Rate | Up to 2.6GPM |
| Wattage | 11kW |
| Voltage | 208~240 Volt |
| Temperature Control | Within 1°F |
| Certification | ETL Certified |
| Dimensions | 14.8 × 11.8 × 3.13 inches |
| Size | 240V/11kW |
| Color | Gray |
| Model | ET110 |
Frequently asked questions
What is the maximum flow rate for this unit?
The Thermomate ET110 delivers 2.15 gallons per minute at a 35°F temperature rise. This flow rate is designed for low-demand applications. It works well for single fixtures like bathroom sinks or small showers. You should not expect high-volume output for multiple simultaneous uses.
Does this heater work with 120V outlets?
No, this unit requires a 240V power source. It is not compatible with standard 120V household outlets. You must install a dedicated 240V circuit to operate the 11kW heating element safely and effectively. Using the wrong voltage will prevent the unit from functioning.
How much wall space does the Thermomate ET110 take up?
The unit measures 11.8 inches in width and 14.8 inches in length. Its depth is only 3.13 inches, making it very slim. This compact footprint allows for easy installation in tight spaces like under a sink or in a small closet without taking up much room.
Is the housing made of plastic or metal?
The housing is made of gray alloy metal. This material choice helps reduce scale, corrosion, and mineral buildup on the internal components. The metal construction provides durability and helps maintain efficient heat transfer over time compared to plastic alternatives.
Can I use this for a whole house?
No, this unit is not suitable for whole-house heating. It is designed for point-of-use applications like a single bathroom or sink. The 11kW capacity and 2.15 GPM flow rate are insufficient for multiple showers or appliances running simultaneously in a large home.
What electrical breakers do I need for installation?
You need two double-pole 30 amp breakers for this unit. The wiring must use 12AWG gauge wire to handle the current safely. These specific electrical requirements are necessary to support the 240V/11kW power draw of the heating element.
How does the temperature control work?
The unit uses self-modulating technology to adjust energy use based on water flow. This system helps maintain precise temperature stability as you adjust the flow rate. You get consistent heat without manual adjustments to the power settings during normal operation.