ThermoMate Electric Tankless Water Heater 11kW - Compact On Demand

In this review of the ThermoMate Electric Tankless Water Heater 11kW, the bottom line is simple: it is a compact, point-of-use solution best suited for a single bathroom, small sink or office break room where endless hot water and space savings matter most. The unit delivers continuous hot water on demand and uses self-modulating technology to only draw energy needed to maintain the set temperature, which is the single biggest reason to consider this heater for low-flow applications.

Key Features

• Endless On Demand Hot Water: Continuously detects inlet temperature and flow rate to provide consistent hot water within 1F of the selected temperature for small fixtures.
• Self Modulating Energy Saving: Regulates power use so the heater only consumes the energy required to heat water, helping reduce water heating costs compared with a traditional tank.
• Compact Wall Mounted Design: The no-tank, space-saving form factor fits tight locations such as under a sink or in a utility closet, freeing floor space.
• Durable Construction: Alloy metal housing and separated heating element help limit scale and corrosion on the element for lower maintenance and longer service life.
• Safety and Protection: ETL certified with overheating protection and automatic shutoff when no water flow is detected to reduce risk of damage.
• Installer-Friendly Connections: 1/2 NPT male ports and clear electrical requirements make it straightforward for a qualified electrician to wire for point-of-use applications.

Who It's For

The ThermoMate 11kW is ideal for homeowners and small business operators who need an efficient, compact heater for a single bathroom, small sink, or break room and who want continuous hot water without a bulky tank. It works well where demand is low to moderate and space is at a premium.

It is not the right choice for large families or whole-house heating where higher flow rates and larger temperature rises are required; those users should consider higher-kW models or multiple units because this 11kW model is rated for point-of-use, low-flow situations.

Pros & Cons

Pros

• Compact wall-mounted design saves floor space and fits under sinks or in tight areas.
• Self-modulating control improves efficiency and can cut water heating costs significantly versus a tank heater.
• Durable alloy housing and separated heating element reduce scale buildup and maintenance needs.
• ETL certified safety features and automatic shutoff add protection for everyday use.

Cons

• Performance depends on inlet temperature and flow; some customers report lukewarm water or limited flow in colder climates or higher demand situations.
• Electrical requirements are significant for the unit class, requiring proper breakers and wiring (two double-pole 30A breakers recommended).

Specifications

Model	11kW ET Series
Power	11 kilowatts
Voltage	208~240 Volt
Max amperage draw	46A (requires 2 x double-pole 30A breakers)
Flow performance	2.15 GPM at 35F rise
Connections	1/2 NPT male ports
Certification	ETL certified

Our Verdict

The ThermoMate 11kW tankless heater is a solid value for point-of-use installations where space is limited and continuous hot water is needed for a single fixture. Its energy-saving self-modulation and durable construction make it a practical, lower-maintenance alternative to a small tank, but buyers should confirm electrical capacity and realistic flow expectations for their climate and application.

Frequently Asked Questions

What breaker size does this unit require?
The unit draws up to about 46A and the recommended setup is two sets of double-pole 30A breakers wired per the installation notes.

Can it heat a whole house?
No, this 11kW model is intended for point-of-use and low-flow applications like a bathroom or small sink; whole-house use requires higher kW capacity or multiple units.

How does it handle scale and corrosion?
Alloy housing and a heating element separated from the water tube reduce scale buildup and corrosion on the element to lower maintenance over time.