APUS 27kW Electric Tankless Water Heater Review: Specs, Pros and Cons

What stands out

• Delivers up to 6.5 GPM for multi-point residential use across three to four fixtures.
• Features digital temperature control from 86°F to 140°F in 1°F increments with memory recall.
• Utilizes self-modulating heating technology to match power output directly to water demand.
• Requires a 240V electrical connection configured with three 40A breakers and 6×8 AWG wiring.

Who it fits

APUS 27kW Key Specs Explained

Voltage: 240V

This unit requires a dedicated 240V electrical circuit, which is standard for most US homes. You must ensure your panel can support this load. The listing specifies needing three 40-amp breakers and 6-gauge wiring. This high voltage allows the heater to operate efficiently without overloading standard 120V outlets. Always verify your home’s electrical capacity before installation to ensure safe and reliable operation.

Wattage: 27kW

The 27-kilowatt heating element determines how much energy the unit uses to heat water. Higher wattage generally supports higher flow rates. This power level is suitable for whole-home use or multiple simultaneous fixtures. It allows the self-modulating technology to adjust output based on demand. Check your electrical panel’s total capacity to ensure it can handle this load alongside other high-draw appliances in your home.

Flow Rate: 6.5 GPM

This maximum flow rate indicates the unit can deliver up to 6.5 gallons per minute. This capacity supports three to four simultaneous uses, such as showers and sinks. Actual flow depends on inlet water temperature and desired output heat. This spec helps you determine if the unit can handle your household’s peak demand. Compare this with other models to ensure it meets your family’s usage patterns.

Temperature Control: 86°F–140°F

You can adjust the output temperature within this range using 1°F increments. This precision allows you to set exact comfort levels for different uses. The digital display and memory function recall your preferred setting. Higher settings are useful for dishwashing, while lower settings may suit handwashing. This range covers most residential needs. Verify that your plumbing and fixtures can handle the maximum temperature safely.

Build Quality and Dimensions

The APUS unit measures 17.7 by 11.4 by 3.5 inches according to the listing. Its compact footprint allows for wall mounting in utility rooms or basements. You save floor space by installing it vertically rather than horizontally. The body weighs 19 pounds, which simplifies handling during installation. You need standard 3/4-inch NPT water connections for plumbing integration. This size supports permanent residential setups without requiring excessive structural reinforcement. The gray finish blends with typical mechanical room aesthetics. You avoid the bulk of traditional storage tanks while maintaining a streamlined profile. The dimensions ensure it fits standard utility spaces without crowding other equipment. You can position it near your main water line for efficient delivery.

Controls feature an LED digital display with 1-degree Fahrenheit adjustments. You set temperatures between 86°F and 140°F with precision. The memory function recalls your last setting, so you do not need to reconfigure the unit daily. Intelligent self-modulating technology adjusts heating output based on real-time flow. This means the system responds instantly to changes in water demand. You get stable comfort without manual intervention. The interface is straightforward, allowing you to monitor and adjust settings easily. You avoid guesswork when selecting your preferred shower temperature. The digital readout provides clear feedback on current operation. You can verify that the unit is functioning within your desired range. This level of control supports consistent performance across different usage scenarios. You maintain hot water reliability for multiple household needs.

Setup and Everyday Use

Installation requires a dedicated 240V electrical circuit. The listing specifies three 40-amp breakers and 6-gauge wiring. You must ensure your electrical panel can support this load. Professional installation is recommended to ensure safe grounding and reliable long-term performance. The unit connects via standard 3/4-inch NPT water fittings. This allows for straightforward integration into existing plumbing systems for permanent residential use. Its compact wall-mounted design saves floor space in utility rooms or basements.

Daily operation is managed through an LED digital display. You can adjust the water temperature from 86°F to 140°F in 1°F increments. This precise control helps you find the exact comfort level you need. The built-in memory function recalls your last setting. This means you do not need to readjust the temperature every time you use the unit. Intelligent self-modulating technology continuously adjusts heating output based on real-time water flow. This helps maintain stable outlet temperatures without standby tank losses.

The system monitors operating temperature, water flow, and electrical conditions. If abnormal conditions are detected, fault information is displayed. This feature supports dependable everyday use by alerting you to potential issues. The 27kW heating element delivers up to 6.5 GPM. This flow rate is ideal for three to four simultaneous uses. You get continuous hot water for showers, sinks, kitchens, and laundry. Actual flow varies with inlet-water temperature and household demand. There is no waiting for a storage tank to recover.

Before You Buy This Unit

Before installing this APUS 27kW heater, verify your electrical panel can handle the load. You need three 40-amp breakers and 6-gauge wiring. This is a high-demand unit, so standard circuits will not suffice. Check your inlet water temperature. The 6.5 GPM flow rate assumes moderate conditions. In very cold climates, the actual flow will drop significantly as the unit prioritizes temperature rise. Plan your plumbing connections. The unit uses standard 3/4-inch NPT fittings, which simplifies integration into existing residential systems. Consider the installation space. Its compact, wall-mounted design saves floor space, but you need adequate clearance for maintenance access. Review the control interface. The LED display offers precise 1-degree adjustments, which is useful for consistent comfort. Compare this model to other 27kW options. Ensure the digital controls and self-modulating features meet your specific needs for stability and ease of use.

Check before you buy

• Confirm your panel supports three 40-amp breakers and 6-gauge wiring.
• Check local inlet water temperature to estimate realistic flow rates.
• Ensure you have standard 3/4-inch NPT plumbing connections available.
• Verify wall space allows for the 17.7-inch height and access.

The product at a glance

1

APUS 27kW 240V Tankless Water Heater

Best for: Large households with 240V electrical capacity

Fuel Type

Electric

Flow Rate

Up to 6.5 GPM

Wattage

27 kW

Installation Location

Indoor

Voltage

240V

Temperature Control

86°F–140°F (1°F increments)

View on Amazon: APUS 27kW 240V Tankless Water Heater Affiliate link

The APUS 27kW unit delivers up to 6.5 GPM of hot water using 240V power. Its compact 17.7-inch wall-mounted design saves space in utility areas. You get precise temperature control from 86°F to 140°F in 1°F increments. The self-modulating heating adjusts output to flow rate. This electric heater suits larger households needing simultaneous multi-point use.

Pros

• High 27kW heating power for up to 6.5 GPM flow
• Precise digital temperature control in 1°F increments
• Self-modulating technology matches power to real-time demand
• Compact wall-mounted body saves floor space

Cons

• Requires three 40A breakers and 6x8 AWG cable
• Heavier 19-pound build requires sturdy mounting
• Limited to residential 240V electrical systems

Good fit if

• You need hot water for 3-4 simultaneous uses
• You have a dedicated 240V electrical panel with sufficient capacity
• You want precise temperature adjustments in small increments

Skip if

• You only have standard 120V household outlets
• You cannot install three 40A circuit breakers
• You need a portable or temporary water heating solution

Verdict: APUS 27kW Electric Tankless Water Heater fits larger households with the electrical capacity to support its high power draw. It provides reliable continuous hot water for multiple bathrooms and sinks when installed correctly.

Specifications side by side

Frequently asked questions

See also

• apus 27kw electric tankless water heater alternatives
• best APUS tankless water heaters under 300
• wintemp 27kw electric tankless water review
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