SR81 / SR868C8 Solar Water Heater Controller

Control Keypad (Left): The main display terminal labeled "System Controller for Solar and Heating Systems". It features a digital LCD screen and buttons hidden behind the front flap to monitor temperatures, system status, and program timed backup heating. Main Controller Box (Right): The larger white plastic enclosure containing the electrical terminal blocks, relays, and main circuit board where the sensors, pumps, and electrical backup heaters are wired. Wiring Bundles (Bottom & Left): Temperature sensor probes (like PT1000 for the roof collector and NTC10K for the storage tank) used to collect temperature differentials.