8.8kW AI Instant Water Heater PCBA

8.8kW AI Instant Electric Water Heater PCBA with Intelligent Temperature Control

The XX-NXS-DJR-10043-XH3-5KEYXS1.0 is an intelligent display control board designed for instant electric water heater applications requiring adjustable heating power, adaptive temperature settings and convenient user operation.

This AI instant water heater control solution supports four selectable heating power levels: 5kW, 6kW, 7.5kW and 8.8kW. It integrates a five-key operating interface, intelligent AI temperature mode, 30–55°C temperature adjustment, 50K NTC temperature sensing and automatic constant-temperature parameter calibration.

One of its key features is an inlet-water-temperature-based preset control function, which automatically selects a target temperature according to predefined inlet water temperature ranges.

With flexible heating power configuration and intelligent temperature adjustment, this PCBA provides a practical control platform for customized instant electric water heaters and OEM/ODM water heating projects.

Four-Level Heating Power Configuration up to 8.8kW

The controller supports four selectable heating power configurations, allowing manufacturers to adapt heating output to different product specifications.

Available heating power settings:

• Level 50: 5kW

• Level 60: 6kW

• Level 70: 7.5kW

• Level 80: 8.8kW

The maximum configurable heating power is 8.8kW.

Users can enter the power-limit setting mode by holding the AI key for approximately five seconds.

The temperature increase and decrease keys can then be used to select the required power level.

After configuration, the selected power limit is automatically saved and the system exits the setting mode.

This multi-level power configuration provides flexibility for manufacturers developing instant water heaters with different heating capacities.

Dual Power Supply Options

The control system supports two auxiliary power supply configurations.

Transformer Power Supply:

85–265VAC

Switching Power Supply:

150–280VAC / 50Hz

During sample verification, the transformer power supply configuration operated continuously for 8 hours at 265VAC without abnormal performance.

The switching power supply configuration also operated continuously for 8 hours at 280VAC without abnormal performance.

These two power supply options provide flexibility for different control board electrical designs.

Note: These voltage ranges refer to the control board power supply configurations, not the rated heating system voltage.

Intelligent AI Temperature Control Mode

One of the main features of this water heater PCBA is its AI temperature mode.

The controller uses predefined inlet water temperature ranges to select corresponding target outlet water temperatures.

The temperature compensation settings are as follows:

• Inlet water temperature 0–5°C: Target temperature 45°C

• Inlet water temperature 6–10°C: Target temperature 44°C

• Inlet water temperature 11–15°C: Target temperature 43°C

• Inlet water temperature 16–20°C: Target temperature 42°C

• Inlet water temperature 21–24°C: Target temperature 41°C

• Inlet water temperature 25–26°C: Target temperature 40°C

• Inlet water temperature 27–28°C: Target temperature 39°C

Users can enter AI mode by briefly pressing the AI key for approximately one second.

When AI mode is activated, the display temperature window shows the corresponding AI preset temperature.

This inlet-water-temperature-based control strategy helps reduce the need for repeated manual temperature adjustment and provides a more convenient operating experience.

Five-Key Intelligent Control Interface

The display control board uses a five-key operating interface.

The five keys provide the following functions:

Power Key:

A short press of approximately one second switches the water heater ON or OFF.

Temperature Increase Key:

A short press adjusts the target temperature upward. Long-press operation supports continuous adjustment.

Temperature Decrease Key:

A short press adjusts the target temperature downward. Long-press operation supports continuous adjustment.

AI Key:

A short press of approximately one second activates AI temperature mode. Holding the key for approximately five seconds enters the actual power-limit setting mode.

Mode Key:

A short press cycles through four preset temperature settings: 38°C, 40°C, 42°C and 45°C.

This five-key interface combines temperature adjustment, intelligent temperature selection and heating power configuration in one compact control panel.

30–55°C Adjustable Temperature Range

The controller supports a normal temperature adjustment range of 30–55°C.

Users can adjust the target temperature through the dedicated temperature increase and decrease keys.

Short-press operation provides convenient temperature adjustment, while long-press operation supports continuous adjustment.

The system also provides four preset temperature options through the mode key:

• 38°C

• 40°C

• 42°C

• 45°C

These settings allow users to quickly select commonly used water temperatures without repeatedly adjusting the temperature manually.

50K NTC Temperature Sensing

The PCBA uses a 50K NTC temperature sensing solution with a reference resistance of 50kΩ at 25°C.

The temperature sensing system monitors water temperature and provides feedback for the heating control process.

The controller supports normal operation at ambient temperatures as low as approximately -15°C.

The NTC sensor works together with the constant-temperature control logic to support temperature monitoring and adjustment under different operating conditions.

Adaptive Constant Temperature Calibration and Memory

The controller supports automatic calibration and memory of constant-temperature parameters.

After the initial learning and calibration process, the system can retain relevant temperature-control parameters for subsequent operation.

This function helps maintain consistent temperature-control settings and reduces the need for repeated manual configuration.

Low Water-Flow Startup

The controller starts heating when water flow reaches approximately 1.4 L/min.

Heating stops when water flow decreases to approximately 1.2 L/min.

This water-flow detection mechanism coordinates heating operation with actual water demand.

The defined startup and shut-off thresholds help ensure that heating is controlled according to the detected water flow conditions.

Digital Display and Buzzer Feedback

The display board provides a digital interface for temperature setting and operating status indication.

The display supports the presentation of relevant temperature information and responds to different operating modes.

The controller also integrates an audible buzzer for operating feedback.

The tested buzzer frequency is 4kHz, matching the specified operating frequency.

This combination of digital display and audible feedback provides a convenient user interaction experience.

Electrical and Environmental Reliability Testing

The complete unit has undergone electrical and environmental verification.

Dielectric Withstand Test:

1800V / 5mA / 1 minute

The complete unit passed the dielectric withstand test under normal ambient conditions without abnormal performance.

Temperature and Humidity Testing:

Operating Temperature Range: -15°C to 65°C

Operating Humidity Range: 10%–95% RH

High-Temperature and Humidity Verification:

65°C / 90% RH for 8 continuous hours without abnormal performance.

Interference Testing:

30 repeated lamp switching cycles at intervals of approximately 0.5–3 seconds without abnormal performance.

These test results provide supporting information for evaluating the controller's electrical and environmental performance.

Suitable Applications

This AI instant water heater PCBA is suitable for:

• High-power instant electric water heaters

• Household instant electric shower heaters

• Multi-power electric water heating systems

• Intelligent temperature-controlled water heaters

• Compact instant hot water equipment

• Water heaters with adaptive temperature settings

• Customized OEM and ODM water heating products

OEM and ODM Customization

Different water heater manufacturers may require different heating capacities, temperature ranges, power configurations, display interfaces and control functions.

SunSam provides customized PCBA development and manufacturing services according to project requirements.

Customization options can include:

• Heating power configurations

• Maximum heating power

• Control board power supply design

• Temperature adjustment range

• Inlet water temperature compensation settings

• AI mode operating logic

• Preset temperature configurations

• Temperature sensor specifications

• Water-flow startup and shut-off thresholds

• Key layout and operating logic

• Digital display interface

• Temperature calibration and memory functions

• PCB dimensions and structure

• Connector configuration

• Firmware and control logic

SunSam provides one-stop PCBA manufacturing support, including component sourcing, PCB fabrication, SMT assembly, DIP processing, product assembly and functional testing.

Our OEM/ODM capabilities support customers from initial sample development and engineering verification through to stable batch production.

An Intelligent 8.8kW Control Solution for Instant Water Heating

With four selectable heating power levels up to 8.8kW, AI-based inlet water temperature compensation, 30–55°C temperature adjustment, 1.4 L/min startup flow, 50K NTC sensing and automatic temperature calibration, this PCBA provides a flexible control platform for intelligent instant electric water heater applications.

Contact SunSam for technical evaluation, customized water heater PCBA development, sample orders and mass-production quotations.