SR501 solar water heater controller is a microcomputer-based fully automatic control system designed for integrated un-pressurized solar thermal systems. Features NEC high-performance MCU, LCD display, ±2℃ temperature control, dual heating power, and comprehensive safety protections.
The SR501 solar water heater controller is a microcomputer-based, fully automatic control system specially designed for integrated un-pressurized solar thermal systems. Built with the latest high-performance NEC microcontroller, this intelligent controller delivers precise, reliable operation for residential and commercial solar heating systems.
All electronic components are manufactured to industrial standards, ensuring stable performance even in harsh environments, including cold temperatures, high heat, and high humidity. A dedicated clock chip guarantees accurate time-based control, making the SR501 ideal for applications requiring scheduled filling, heating, and pipe insulation.
With a clear LCD display, sleek design, and easy installation, the SR501 controller has become the preferred choice for solar water heater manufacturers and installers worldwide. It is engineered for optimal compatibility with both tap water and low-pressure water supply systems, adapting to diverse global installation requirements.
Latest NEC high-performance MCU: Fast, responsive control logic with stable performance
Comprehensive safety protections: Anti-freezing, overheat, overflow, low-pressure, tank high-temperature safeguards
Flexible heating power options: Heating element support for ≤1500W / ≤3000W (dual model options)
Precise temperature management: ±2℃ accuracy for tank temperature measurements and control
Multi-functional timing control: Three-section timed water filling, heating and recirculation
Intelligent water management: Constant water level filling, temperature-controlled filling, low water level delay filling
User-friendly operation: Celsius/Fahrenheit unit switch, manual override functions, error code display
Low-maintenance design: Industrial-grade components, memory protection for power outages, screen saver function
Versatile valve compatibility: DC 12V / AC 220V solenoid valves (pressure or low-pressure type)
| Parameter | Specification |
|---|---|
| Model | SR501 Solar Water Heater Controller |
| Housing Dimensions | 205mm × 150mm × 50mm |
| Power Supply | 100–240V AC, 50Hz |
| Temperature Measurement Accuracy | ±2℃ |
| Tank Temperature Measuring Range | 0℃ ~ 99℃ |
| Temperature Control Accuracy | ±2℃ |
| Maximum Water Loading Pump Power | ≤200W |
| Maximum Heating Cable Power | ≤600W |
| Maximum Electric Backup Heating Power | ≤1500W / ≤3000W (Two models optional) |
| Solenoid Valve Options | DC 12V / AC 220V (pressure or low-pressure type) |
| Pressure Valve Working Pressure | 0.02MPa ~ 0.8MPa (for direct tap water supply) |
| Low-Pressure Valve Working Pressure | 0.0MPa (for tank-fed or low-pressure water supply) |
| Water Proof Grade | IP40 (industrial-grade protection) |
Clock setting for accurate time scheduling
Three-section timed water filling and backup heating
Temperature controlled automatic water loading
CTHC (Constant Temperature Heating Control) function
LWPR (Low Water Pressure Protection) function
CWL (Constant Water Level Filling) (preset 100% tank water level)
Water filling pump (PUMP) control function
TCYC (Temperature/Flow Recirculation) within three time-sections
AH (Automatic Thermostat) function
OTF (Three Time-Sections Setting) for customized operation
TKPR (Tank High Temperature Protection) function
CFR (Tank Anti-Freezing Protection) function
LWS (Preset Water Level Filling) for low water tank conditions
LWSD (Delayed Water Filling) for low water tank conditions
OTDI (Thermal Disinfection) function for hygienic water supply
Celsius/Fahrenheit temperature unit switch for international use
BEEP (Beeper Error Warning) system for quick fault alerts
Manual water filling override option
Forced water filling function for emergency use
Manual heating override option
Manual DHW (Domestic Hot Water) circulation control
Manual factory reset function for easy configuration restoration
Water level & water temperature sensor sensitivity adjustment
Pipe anti-freezing protection function
Real-time measuring value viewing function
Overflow protection to avoid water waste and damage
Collector tube high temperature protection function
Memory protection to retain settings during power outages
Screen protection (screen saver) function to extend display life
Comprehensive trouble protection system
Detailed error code description for easy troubleshooting
The SR501 solar controller is widely used with integrated un-pressurized solar thermal systems, including residential solar heating systems, small commercial installations, and off-grid solar water heating projects. It is compatible with both direct tap water and low-pressure tank-fed water supplies, making it a versatile solution for different installation scenarios across global markets.
