HS-SXH-5621 Instant Electric Water Heater PCBA

Model 07 – Water Circulation Instant Electric Water Heater PCBA

HS-SXH-5621 8-Key Instant Electric Water Heater PCBA from SUNSAM gives OEM buyers a multifunctional control platform for pump-assisted hot-water equipment. Temperature adjustment, timed operation, three pump levels, cleaning, lighting and voice prompts are integrated into one control board.

The complete PCBA model is HS-SXH-5621-8KEY-C1.0. An integrated board structure combines the MCU, touch-key interface, digital display, water-pump control and temperature-monitoring functions.

AC 150–280 V Switch-Mode Power Supply

The tested switch-mode power supply version operates from AC 150–280 V at 50 Hz. The sample completed eight hours of continuous operation at AC 280 V without abnormal performance.

The test report also lists a transformer-based configuration operating from AC 85–265 V. The transformer and switch-mode configurations represent separate hardware versions. Customers should select the required power supply architecture before sample development.

Rated heating power is not specified in the sample report. Heating-element power, output components, terminals, wiring and thermal requirements must therefore be evaluated for each OEM project.

Water-Pump Control with Delayed Heating Start

A dedicated Water Pump key allows independent pump activation and deactivation. After pump activation, the control system runs the pump for ten seconds before heating begins.

The ten-second pre-run period allows water to circulate before the heating output starts. Final control performance depends on the selected water pump, flow sensor, pipeline structure and heating system.

The Mode key provides three pump levels:

- P1

- P2

- P3

P2 is the default pump setting. Pump levels and operating logic can be adjusted through firmware development according to the selected water pump and target application.

Temperature Adjustment from 30°C to 55°C

The adjustable temperature range covers 30–55°C. Separate Increase and Decrease keys allow single-step or continuous temperature adjustment.

A short press changes the setting step by step. A long press lasting more than one second provides continuous adjustment.

A 50 kΩ NTC temperature sensor supports temperature measurement. Automatic calibration and parameter memory retain the constant-temperature control settings after setup.

The report does not provide completed temperature-accuracy or stabilization-time measurements. Quantitative temperature-control claims should therefore be confirmed through final sample testing.

Adjustable Timer from 5 to 90 Minutes

Independent Timer Increase and Timer Decrease keys provide an adjustable operating period from 5 to 90 minutes.

A short press changes the timer step by step. Long-press operation supports continuous timer adjustment.

The digital display shows the timer setting in minutes. Timed operation can support controlled usage periods for pump-assisted hot-water appliances, cleaning equipment and customized circulation systems.

Three-Minute Cleaning Mode

A dedicated Cleaning key starts or stops the cleaning program while the system is powered on. The programmed cleaning cycle runs for three minutes.

Cleaning duration, pump operation and related output logic can be modified according to customer requirements. Final firmware settings should match the hydraulic structure and cleaning procedure of the complete appliance.

Independent Lighting Control

A dedicated Lighting key provides independent on/off control for a connected light output.

The original test report names the function “Light Therapy.” Website descriptions should use “Lighting Control” unless the complete appliance has verified light-source specifications and relevant supporting test data.

SUNSAM can adjust the lighting-output logic, key icon and display indication according to the required lamp or LED module.

Eight-Key Touch-Control Interface

The control panel contains eight touch keys:

- Water Pump On/Off

- Temperature Increase

- Temperature Decrease

- Timer Increase

- Timer Decrease

- Pump Mode

- Lighting

- Cleaning

The touch keys can operate through a surface-mounted 4 mm glass panel or a 2 mm plastic panel. Such compatibility supports different front-panel materials, graphics and appliance designs.

Eight red LED indicators provide key or status illumination. The LED color, key graphics and panel layout can be adjusted during OEM or ODM development.

Digital Display Information

The digital display supports the following information:

- Actual outlet water temperature

- Set temperature

- Timer setting in minutes

- Fault codes

Characters, display segments and icons were inspected for uniform brightness during the sample test.

Voice Prompt Function

The control board provides voice prompts for selected operations and faults. Available prompts include:

- Temperature increase or decrease

- Timer increase or decrease

- Cleaning mode on or off

- Lighting function on

- Standard Mode

- Surf Mode

- Outlet temperature sensor fault

Voice Prompt refers to prerecorded audible messages. Voice-command recognition or remote voice control is not included in the tested sample.

Prompt language, audio content and operating sequence can be customized according to the target market and appliance functions.

Outlet Temperature Sensor Protection

The E2 fault function monitors the outlet temperature sensor for open-circuit and short-circuit conditions.

When an outlet sensor fault is detected, the controller displays the fault code, provides a voice alarm and stops heating. Normal operation resumes after fault clearance and a power cycle.

The report lists a leakage-protection target range of 15–30 mA but does not provide a measured sample result. A numerical leakage trip value should be published only after completed verification.

Main Technical Specifications

| Parameter | Specification |

|---|---|

| Product Name | HS-SXH-5621 8-Key Instant Electric Water Heater PCBA |

| Complete PCBA Model | HS-SXH-5621-8KEY-C1.0 |

| Control Board Structure | Integrated Control Board |

| Controller Chip | Lingxin Micro MCU |

| Power Supply Design | Switch-Mode Power Supply |

| Operating Voltage | AC 150–280 V |

| Operating Frequency | 50 Hz |

| Temperature Setting Range | 30–55°C |

| Timer Range | 5–90 Minutes |

| Pump Levels | P1, P2 and P3 |

| Default Pump Level | P2 |

| Pump Pre-Run Time | 10 Seconds Before Heating |

| Cleaning Cycle | 3 Minutes |

| Control Interface | Eight-Key Touch Control |

| LED Configuration | Eight Red LED Indicators |

| Panel Compatibility | 4 mm Glass or 2 mm Plastic |

| Display Information | Outlet Temperature, Set Temperature, Timer and Fault Codes |

| Temperature Sensor | 50 kΩ NTC at 25°C |

| Parameter Memory | Automatic Calibration and Memory |

| Operating Temperature | −15°C to 65°C |

| Operating Humidity | 10%–95% RH |

Sample Testing and Verification

The sample test report records the following verification results:

- Eight hours of continuous operation at AC 280 V

- Eight hours of operation at 65°C and 90% relative humidity

- Normal temperature-sensor operation at −15°C

- No abnormal performance after 30 switching-interference cycles

- Complete-unit dielectric withstand test at 1,800 V, 5 mA for one minute

- Uniform brightness across display characters, segments and icons

- Outlet temperature sensor fault detection and heating cut-off

Recorded results apply to the tested sample and stated test conditions. Final electrical, temperature-control and safety performance requires verification after integration into the complete appliance.

Water Heater PCBA Development and Manufacturing

Water heater control boards account for approximately 70% of SUNSAM’s current PCBA production. Fifteen years of customized PCBA experience support manufacturers from functional evaluation and sample development to batch production.

SUNSAM provides:

- Hardware circuit development

- Embedded firmware development

- Existing PCBA sample analysis

- PCB layout and PCBA redesign

- Voice prompt customization

- Touch-panel interface development

- Water-pump and sensor matching

- Electronic component sourcing

- SMT and DIP assembly

- Wave soldering

- Functional testing

- IPQC and IPQA inspection

- Production traceability

- Prototype and volume manufacturing

Material, work-in-process and finished-product traceability can be arranged according to project requirements. Production planning and component selection depend on the confirmed functions, BOM, estimated quantity and destination-market standards.

More control board solutions are available on the [SUNSAM PCBA product page](https://www.sunsampcba.com/products.html).

Applications

The HS-SXH-5621 control platform can support:

- Pump-assisted instant electric water heaters

- Multifunctional shower systems

- Compact hot-water circulation appliances

- Timed hot-water equipment

- Cleaning equipment with controlled water heating

- Customized bathroom and personal-care appliances

- OEM and ODM hot-water products

Applications involving light therapy or personal-care functions require product-level validation and appropriate compliance assessment. No medical or therapeutic performance claim is included in the PCBA specification.

Frequently Asked Questions

What functions are integrated into the HS-SXH-5621?

The control board integrates water-pump operation, temperature adjustment, a 5–90 minute timer, three pump levels, a three-minute cleaning cycle, lighting control, voice prompts and digital display functions.

What heating power does the PCBA support?

The sample report does not specify a rated heating power. Customers should provide the heating-element voltage, power, current and wiring requirements for engineering evaluation.

What are the water-flow activation and shut-off values?

The sample report leaves both values blank. Flow thresholds require confirmation after matching the flow sensor, pump and hydraulic system.

Does the PCBA support voice control?

The tested sample supports prerecorded voice prompts. Voice recognition and voice-command control are not included.

Can the voice content and language be customized?

Yes. Prompt language, audio content and operating sequences can be developed according to the target market and project requirements.

Can the panel layout be customized?

Yes. Key graphics, display content, LED colors and panel layouts can be adjusted after hardware and firmware evaluation.

What information is required for a quotation?

An existing sample, functional specification, PCBA dimensions, heating-element information, pump model, sensor specifications, display requirements, wiring diagram and estimated order quantity can support technical and cost evaluation.

Is sample validation required before mass production?

Yes. The PCBA must be matched with the water pump, heating element, temperature sensors, display panel, wiring and complete hydraulic system. Prototype validation should be completed before batch production.