The Power Reducer RC (PR-RC) from Astrel Group's 4-noks brand is a wireless controller that captures surplus energy from a photovoltaic system and uses it to heat domestic hot water — the most cost-effective thermal storage available in most homes. Unlike timer-based immersion controllers that may draw from the grid, the PR-RC modulates power to the heating element linearly from 0 to 100% in real time, matching exactly the available PV surplus moment by moment. The RC variant communicates wirelessly with Elios4you Smart (single-phase up to 6 kW) or Elios4you Pro Smart (three-phase up to 100 kW) controllers, eliminating any control wiring between the inverter monitor and the water heater location.

How does linear power modulation maximize self-consumption?

Conventional PV diverters switch the immersion heater fully on or off at fixed thresholds, which means surplus below the heater's rated power is exported to the grid and surplus above is wasted as the heater cannot absorb it. The PR-RC continuously varies the power absorbed by the heating element — at one moment diverting 450 W because a cloud passed over, at the next ramping to 2.8 kW as the sun returns — ensuring the household consumes every watt of PV generation that would otherwise be exported. When the water tank reaches its target temperature and no further storage is available, surplus reverts to grid export. A boost function with programmable weekly timer guarantees hot water availability during extended cloudy periods by temporarily allowing grid-powered heating.

What installation and configuration does the RC wireless model require?

The PR-RC is installed electrically near the water heater or immersion tank — incoming mains supply and outgoing load connections use screw terminals, with a 20 A internal fuse protecting the circuit. No plumbing work is needed. The RC variant communicates with the Elios4you controller over radio frequency, removing the need to run a control cable between the inverter area and the hot water cupboard. Configuration is performed entirely through the free Elios4you app, which provides real-time power flow visualization, historical energy diversion statistics, and boost timer programming. LED indicators on the unit show power-on status, boost activation, and a brightness-proportional power level display.