CD 5.5kW Pump-Control Water Heater PCBA

5.5kW Instant Electric Water Heater PCBA with Adjustable Water Pump Control

The XX-CD-31N1-DYB1.0 is a 220V, 5.5kW instant electric water heater PCBA designed for water heating systems requiring adjustable water pump operation, temperature regulation and reliable fault protection.

This split-type water heater control board combines a dual-knob operating interface, 0–10 level water pump adjustment, independent pump ON/OFF control, 30–55°C temperature settings, digital temperature display, self-test functionality and multiple protection mechanisms.

Designed for customized electric water heating equipment, the controller provides an integrated solution for managing heating operation and water pump performance.

220V / 5.5kW Heating Control

The PCBA is designed for 220V instant electric water heater applications with a rated heating power configuration of 5.5kW.

The control system coordinates heating operation with water flow and temperature settings, allowing the water heater to respond to different operating requirements.

The 5.5kW power configuration makes the board suitable for compact electric water heating systems, pump-assisted water heaters and customized OEM/ODM heating equipment.

Dual Power Supply Options

The control board 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 options provide flexibility for manufacturers developing products with different electrical designs.

The rated heating system voltage is 220V, while the above voltage ranges refer to the control board power supply configurations.

Adjustable 0–10 Level Water Pump Control

One of the key features of this instant electric water heater PCBA is its adjustable water pump control function.

The controller provides a dedicated rotary knob for adjusting water pump operation across levels 0–10.

Rotating the knob clockwise increases the selected pump level, while rotating it counterclockwise decreases the level.

This adjustable pump control interface allows users to select the required pump setting according to the operating conditions of the water heating system.

For manufacturers developing pump-assisted instant electric water heaters, this function provides a practical method for integrating water pump adjustment directly into the heating control interface.

Independent Water Pump ON/OFF Control

The controller includes a dedicated water pump power key.

A short press activates or deactivates the water pump function.

The independent pump control function allows the water pump to be operated through its own control interface rather than relying solely on the temperature adjustment controls.

This design is suitable for water heating equipment requiring separate control of heating-related and pump-related functions.

30–55°C Adjustable Temperature Control

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

Users can adjust the target temperature through a dedicated rotary temperature control knob.

Clockwise rotation increases the temperature setting, while counterclockwise rotation decreases it.

The control system provides convenient temperature adjustment for different hot water requirements.

The temperature adjustment interface is designed to support controlled heating operation within the specified temperature range.

Dual-Knob Control Interface

The XX-CD-31N1-DYB1.0 uses a practical dual-knob operating structure.

Temperature Control Knob:

Adjusts the target outlet water temperature within the specified 30–55°C range.

Water Pump Control Knob:

Provides adjustable water pump levels from 0 to 10.

In addition to the rotary controls, the PCBA supports dedicated operating keys for pump control, fault reset and system self-testing.

This combination of rotary controls and function keys provides a straightforward user interface for water heating applications.

Low Water-Flow Startup

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

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

This flow detection function helps coordinate heating operation with actual water demand.

The defined startup and shut-off thresholds also help prevent heating operation when the detected water flow is below the required level.

NTC Temperature Sensing

The PCBA uses an NTC temperature sensing solution for monitoring water temperature and supporting heating regulation.

Temperature sensing is integrated with the control logic to monitor actual outlet water temperature and identify abnormal sensor conditions.

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

This temperature sensing design provides a practical foundation for stable water heater operation under different environmental conditions.

Adaptive Constant Temperature Control

The control board supports automatic constant-temperature parameter calibration and memory.

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

The sample testing covered different outlet temperature settings under water-flow conditions of 1.5 L/min and 3 L/min.

Tested temperature settings included 36°C, 40°C, 45°C and 48°C.

The measured temperature ranges remained close to the corresponding target temperatures under the specified test conditions.

For example:

At 1.5 L/min:

36°C Setting: 35–37°C

40°C Setting: 40–42°C

45°C Setting: 44–46°C

48°C Setting: 48–50°C

At 3 L/min:

36°C Setting: 36–37°C

40°C Setting: 39–42°C

45°C Setting: 44–46°C

48°C Setting: 47–49°C

These results provide reference data for evaluating the controller's constant-temperature performance under different water-flow conditions.

Actual temperature stabilization depends on inlet water temperature, water flow and heating conditions.

Digital Display and Operating Status Indication

The control board supports a digital display for operating information.

The display can show:

• Selected temperature

• Actual outlet water temperature

• Fault codes

• Water pump level

The system also includes LED indicators for operating and fault status.

The red LED indicates that the system is operating in heating mode.

An orange LED provides leakage-related fault or self-test indication.

This combination of digital display and LED status indicators helps users and maintenance personnel identify operating conditions more easily.

Fault Reset Function

The controller includes a dedicated reset key.

When the system detects a fault, the reset function can be used as part of the fault recovery process.

This design provides convenient access to the controller's fault handling functions and supports maintenance operations after the underlying abnormal condition has been addressed.

Power-On Self-Test Function

The PCBA supports a dedicated self-test function.

A short press of approximately one second activates the corresponding self-test operation.

The self-test function provides an additional operating feature for checking the control system during product operation or maintenance.

Integrated Fault Detection and Protection

The control board includes multiple fault detection functions designed for instant electric water heating applications.

The tested fault functions include:

• Over-temperature protection

• Leakage fault detection

• Outlet temperature sensor open-circuit detection

• Outlet temperature sensor short-circuit detection

• Zero-crossing abnormality detection

• Fault status indication

• Heating control under abnormal conditions

These functions provide diagnostic information and support protective control when abnormal operating conditions are detected.

Over-Temperature Protection

The controller supports an over-temperature protection function.

When the detected temperature reaches or exceeds approximately 65°C, the system activates an alarm and stops heating.

When the temperature decreases below approximately 50°C, the system can automatically return to normal operation according to the control logic.

This protection mechanism helps prevent continued heating during abnormal high-temperature conditions.

Leakage Fault Protection

The PCBA supports leakage fault detection and fault indication.

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

After the fault has been eliminated, the system can return to normal operation through the specified restart procedure.

The digital display and LED indicators provide information to help identify abnormal conditions.

Outlet Temperature Sensor Fault Detection

The controller monitors the outlet water temperature sensor for abnormal conditions.

If the sensor experiences an open-circuit or short-circuit fault, the controller displays the corresponding error indication and stops heating.

After the fault has been corrected, the system can automatically recover according to the programmed control logic.

Fault Code Diagnosis

The controller supports fault code indication to simplify maintenance and troubleshooting.

E1 – Leakage Fault

Heating is stopped when a leakage-related fault is detected. After the fault is eliminated and the controller is restarted, normal operation can resume.

E2 – Over-Temperature Fault

When the detected temperature reaches approximately 65°C or above, the system activates an alarm and stops heating.

Normal operation can resume automatically after the temperature falls below approximately 50°C.

E3 – Outlet Temperature Sensor Fault

The controller identifies outlet temperature sensor open-circuit or short-circuit conditions and stops heating until the abnormal condition is eliminated.

Zero-crossing abnormalities are also monitored by the control system, with a corresponding fault-handling and recovery process.

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.

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 switching cycles with intervals of approximately 0.5–3 seconds without abnormal performance.

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

Suitable Applications

This 220V 5.5kW instant water heater PCBA is suitable for:

• Pump-assisted instant electric water heaters

• Household instant electric water heaters

• Electric shower heating equipment

• Compact water heating systems

• Water heaters with adjustable pump operation

• Temperature-controlled water heating appliances

• Customized OEM and ODM water heater projects

OEM and ODM Customization

Different water heater manufacturers may require different heating capacities, pump control configurations, PCB dimensions, temperature ranges and user interfaces.

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

Customization options can include:

• Rated heating voltage and power

• Water pump speed control levels

• Water pump ON/OFF logic

• Temperature adjustment range

• Temperature sensor configuration

• Water-flow startup thresholds

• Rotary knob interface

• Digital display layout

• LED status indication

• Fault reset and self-test functions

• Over-temperature protection logic

• Leakage fault detection

• PCB dimensions and connector configuration

• Firmware and control logic

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

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

A Flexible Pump-Control Solution for Instant Water Heaters

The XX-CD-31N1-DYB1.0 combines a 220V / 5.5kW heating configuration, 0–10 level water pump control, 30–55°C temperature adjustment, 1.4 L/min startup flow, NTC temperature sensing and multiple fault protection functions.

With its practical dual-knob interface, independent pump control, digital display and self-test functionality, this PCBA provides a flexible control platform for customized instant electric water heating applications.

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