NRG Lex V3.2

Designed for domestic and light commercial applications, the NRG Lex v3.2 is equally suited to traditional boiler systems and modern hybrid installations combining heat pumps with boilers. It provides clear logic, built‑in safety, and flexible control options for today’s increasingly complex heating layouts. 

What the NRG Lex v3.2 does

At its core, the NRG Lex v3.2 acts as the electrical brain of the heating system. It manages:

• Up to four independent heating or hot water zones
• Control of multiple heat sources (boilers, heat pumps, or both)
• Domestic hot water (DHW) priority
• Auxiliary functions such as large pumps, solid fuel interlocks, or external controls

All zone calls, appliance calls, and auxiliary operations are handled through clearly labelled terminals with live status indication, making system behaviour easy to understand during installation and fault‑finding.

Built for Hybrid Heating Systems

One of the key advancements in the v3.2 model is its built‑in hybrid control functionality.

The unit can independently control two different types of heat sources, for example:

• A heat pump as the primary appliance
• A boiler as a secondary or high‑temperature backup

Using onboard microswitches and time‑delay logic, the NRG Lex v3.2 can be configured to bring on the secondary heat source only when required—such as during high load, low outdoor temperature, or extended zone demand. This allows installers to implement proven hybrid strategies without external controllers or bespoke wiring solutions. 

Installer‑Focused Design

The NRG Lex v3.2 has been developed with installers in mind:

• Pre‑configured logic reduces design time
• Push‑open terminals accept standard 0.5–1.5 mm² cables
• Individual fused outputs protect zones, boilers, and controls
• LED indicators show zone calls, boiler calls, auxiliary outputs, and system status
• Relay test switches allow safe commissioning without external calls

The enlarged enclosure compared to earlier versions provides improved cable management and easier access during installation and servicing.

Flexible Control for Real‑World Systems

The NRG Lex v3.2 supports a wide range of common control methods and system layouts, including:

• Pumps or motorised valves (S‑plan and Y‑plan style systems)
• Programmable thermostats and multi‑channel time controls
• Switch‑live and volt‑free boiler inputs
• DHW priority on Zone A
• Interlinking of multiple NRG Lex units for larger systems

Three double‑pole auxiliary relays allow the control of higher‑load components or advanced interlocks, making the Lex suitable for systems involving solid fuel appliances, buffer tanks, or non‑standard zone arrangements. 

Typical Applications

• Zoned radiator and underfloor heating systems
• Heat pump systems with multiple heating zones
• Hybrid heat pump and boiler installations
• Systems requiring clear electrical separation and safety control
• Installations where fast commissioning and future serviceability matter