220V 800W 6-Key Instant Water Heater PCBA

220V 800W Instant Electric Water Heater PCBA with 6-Key Control, Timer and Cleaning Functions

The XX-HXD-CS-2RLY-ZB1.0 main control board and XX-HXD-CS-6KEY-XH3-XS1.0 display board form a split-type control solution designed for 220V instant electric water heater applications.

This 800W water heater PCBA integrates a six-key operating interface, 30–55°C temperature adjustment, programmable timer, lighting control, cleaning mode and intelligent temperature memory.

The control system also features 50K NTC temperature sensing, automatic constant-temperature parameter calibration, digital display and multiple fault detection functions.

With its integrated operating functions and flexible control configuration, this PCBA provides a practical solution for household instant water heaters and customized OEM/ODM water heating equipment.

Split-Type Main Control and Display Board Design

This product adopts a split-board architecture consisting of two independent PCB assemblies.

Main Control Board:

XX-HXD-CS-2RLY-ZB1.0

Display Board:

XX-HXD-CS-6KEY-XH3-XS1.0

The main control board manages heating-related operations and control logic, while the display board provides user interaction, temperature adjustment, timer settings and operating status indication.

This configuration provides flexibility for water heater manufacturers when designing the internal structure and user interface of finished appliances.

220V / 800W Power Configuration

The control solution is designed for a 220V, 800W product configuration.

It supports two control board auxiliary power supply options:

Transformer Power Supply:

180–265VAC

Switching Power Supply:

85–270VAC / 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 270VAC without abnormal performance.

These power supply options provide flexibility for different electrical designs.

Note: The above voltage ranges refer to the control board power supply configurations. The rated product configuration is 220V / 800W.

Six-Key Intelligent Control Interface

The display board features a six-key control interface designed to simplify daily operation and provide multiple functional settings.

The six operating functions include:

1. Power Key

2. Temperature Increase Key

3. Temperature Decrease Key

4. Lighting Key

5. Timer Key

6. Cleaning Key

Each key provides dedicated operating functions, allowing users to control temperature, lighting, timing and cleaning modes through a single interface.

Intelligent Power ON/OFF Control

The power key supports short-press operation of approximately one second to switch the water heater ON or OFF.

When the unit is switched on, the water pump operates for approximately 10 seconds before heating begins.

When the unit is switched off, the digital display turns off while the power key LED remains illuminated.

This startup sequence helps coordinate the water pump and heating control process.

30–55°C Adjustable Temperature Control

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

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

Short Press:

Adjusts the target temperature by approximately 1°C per operation.

Long Press:

Holding either temperature key for more than one second enables continuous temperature adjustment.

This control method provides convenient temperature selection for different hot water requirements.

Programmable 5–60 Minute Timer

The PCBA integrates a programmable timer function for scheduled operation.

The timer supports an adjustable range of 5–60 minutes, with a default setting of 30 minutes.

Timer adjustment features include:

• Short-press operation adjusts the timer in 5-minute increments.

• Long-press operation supports continuous timer adjustment.

• The timer setting can cycle within the available 5–60 minute range.

The remaining or configured timer duration is displayed through the digital display.

This function provides convenient operating-time management for water heating applications.

Independent Lighting Control

The controller integrates a dedicated lighting control key.

Users can switch the lighting function ON or OFF through a short press of approximately one second.

This independent control function allows the lighting system to operate according to user requirements without changing the main temperature settings.

Three-Minute Cleaning Function

A dedicated cleaning key provides an additional cleaning operating mode.

In the powered-on state, a short press of approximately one second activates the three-minute cleaning function.

The cleaning operation automatically exits after approximately three minutes.

In the powered-off state, the cleaning key also supports its corresponding indicator control, with the key LED showing the selected status.

This integrated function provides additional operating convenience for water heater products requiring a dedicated cleaning mode.

50K NTC Temperature Sensing

The controller uses a 50K NTC temperature sensor configuration with a reference resistance of 50kΩ at 25°C.

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

The control board also supports normal operation at ambient temperatures as low as approximately -15°C.

This sensor configuration helps the controller perform temperature monitoring and adjustment under different operating conditions.

Automatic Temperature Calibration and Memory

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

This function helps maintain the configured temperature-control parameters during repeated operation.

The controller integrates temperature memory logic to improve operating convenience and reduce the need for repeated manual adjustment.

Digital Display and Operating Status Indication

The display board provides clear operating information through a digital display.

The temperature display supports three main functions:

• Normal operation: Displays the actual outlet water temperature.

• Temperature adjustment: Displays the selected target temperature.

• System fault: Displays the corresponding fault code.

The timer display shows the configured operating time within the 05–60 minute range.

The heating status is indicated by a dynamic heating icon, allowing users to identify when the heating function is active.

The display design provides clear visual feedback for different operating modes.

Buzzer Feedback

The PCBA integrates an audible buzzer for operating feedback.

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

The buzzer provides audible feedback during operation while maintaining a moderate sound level.

Multiple Fault Detection and Protection Functions

The controller integrates fault detection functions for outlet water temperature sensor abnormalities and leakage-related faults.

The tested fault codes include:

E2 – Outlet Water Temperature Sensor Fault

This fault is triggered when the outlet temperature sensor experiences an open-circuit or short-circuit condition.

The display flashes to indicate the abnormal condition. After the fault is eliminated, the heating function can resume.

E0 – Leakage Fault

When a leakage-related fault is detected, heating operation is stopped.

After the fault is eliminated and the unit is restarted, the system can automatically return to normal operation.

These fault detection functions help improve operating safety and simplify troubleshooting during maintenance.

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 85°C

Operating Humidity Range: 10%–95% RH

High-Temperature and Humidity Verification:

85°C / 85% RH for 8 continuous hours without abnormal performance.

Interference Testing:

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

These verification results provide a reference for manufacturers evaluating the control board for different operating environments.

Suitable Applications

This 220V 800W instant water heater PCBA can be used in:

• Household instant electric water heaters

• Compact electric water heating equipment

• Bathroom water heating systems

• Water heaters with integrated lighting functions

• Water heating appliances with timer control

• Water heaters requiring dedicated cleaning functions

• Customized OEM and ODM water heating products

OEM and ODM Customization

Different water heater manufacturers may require different PCB dimensions, control interfaces, display layouts, temperature ranges and operating functions.

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

Customization options can include:

• Main control board and display board architecture

• Rated voltage and power configuration

• Temperature adjustment range

• Temperature sensor specifications

• Timer functions and operating duration

• Lighting control functions

• Cleaning mode configuration

• Key layout and operating logic

• Digital display interface

• Temperature calibration and memory logic

• Fault detection and protection functions

• PCB dimensions and 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 sample development and engineering verification through to stable mass production.

A Flexible Control Solution for Customized Water Heating Products

With a split-type main and display board design, 220V / 800W configuration, six-key operating interface, 30–55°C temperature adjustment, 5–60 minute timer, independent lighting control, three-minute cleaning mode and 50K NTC temperature sensing, this PCBA provides a versatile control platform for customized instant electric water heater applications.

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