Marlec Solar iBoost+ – Solar Immersion Controller

The Marlec Solar iBoost+ is a solar PV immersion controller that automatically diverts surplus solar electricity into your hot water cylinder instead of exporting it to the grid. It is designed for homes with solar PV and a conventional immersion heater, helping you use more of the electricity you generate and reduce the energy needed to heat water.

The system monitors electricity flowing to and from the grid using a clamp and wireless Sender. When surplus generation is detected, the Solar iBoost+ varies the power sent to the immersion heater to match the available excess energy. It can begin diverting from around 100W of surplus power and control immersion loads up to 3kW.

Why choose the Marlec Solar iBoost+?

• Use surplus solar for hot water: automatically diverts excess solar PV generation to your immersion heater.
• 100W to 3kW power diversion: responds to changing generation and household demand rather than simply switching a fixed load on and off.
• Battery storage compatible: adjustable cut-in threshold allows battery charging or water heating to be prioritised.
• Supports two immersion heaters: suitable for cylinders with dual immersions.
• Manual Boost and programmable timer: top up hot water when required.
• Built-in savings display: monitor diverted energy over multiple time periods.
• 2-year manufacturer warranty.

How does the Solar iBoost+ Work?

1. Your PV solar array generates electricity used in real-time in your home, reducing dependence on the grid and lowering energy bills. Any excess energy is typically exported to the grid, maximising efficiency, cutting costs, and supporting sustainability.
2. Solar iBoost’s Sender and Clamp are installed at the household electricity meter. The Clamp detects when excess energy is available, and the Sender wirelessly sends a signal to the Solar iBoost+ to activate water heating.
3. The Solar iBoost+ control unit is installed next to the hot water tank and receives messages from the Sender.  When activated, it intelligently controls and adjusts the level of energy flowing to your immersion heater in line with the export levels as they rise and fall.

Solar iBoost+ and home battery storage

The Solar iBoost+ can be used alongside home battery storage. Its export cut-in threshold is adjustable from the standard 100W setting in 50W increments up to 500W. This allows the system to be configured so, for example, the battery is charged before surplus power is sent to the immersion heater.

For reliable operation, the Solar iBoost+ and battery system should be configured with appropriate and separate operating thresholds by the installer.

What is included?

• Solar iBoost+ main controller
• Wireless Sender unit with 2 x AA batteries
• Current-sensing clamp and cable
• Fixing screws
• Installation and user documentation
• Installation template and commissioning documentation

Solar iBoost+ specifications

• Immersion heater load: up to 3kW / 13A resistive
• Operating voltage: 220–240V AC
• Standard export cut-in threshold: 100W
• Adjustable cut-in threshold: 100W–500W
• Controller dimensions: approximately 225 x 158 x 92mm
• Controller weight: approximately 1.37kg
• Sender wireless range: up to 30m indoors, dependent on building construction and local conditions
• Warranty: 2 years

Optional Solar iBoost+ Buddy

For remote monitoring and control from elsewhere in the home, the optional Solar iBoost+ Buddy Monitor V2 can display import/export status, diverted-energy savings and allow remote control of the Boost function.

Solar iBoost+ FAQs

What does a Solar iBoost do?

A Solar iBoost is a solar immersion diverter. It detects surplus electricity from a solar PV system and sends that spare energy to an immersion heater, helping heat stored hot water instead of exporting all of the excess electricity to the grid.

Can Solar iBoost+ work with a home battery?

Yes. Marlec provides an adjustable cut-in threshold specifically to help the Solar iBoost+ operate alongside battery storage. The settings can be configured to prioritise battery charging or hot water depending on the system design.

Does Solar iBoost+ work with two immersion heaters?

Yes. The Solar iBoost+ can control up to two immersion heaters in the same hot water cylinder.

How much surplus solar does Solar iBoost+ need?

The standard cut-in threshold is 100W of export. Once sufficient surplus is available, the controller varies the energy sent to the immersion heater up to a maximum 3kW load.

Does Solar iBoost+ have Wi-Fi or a smartphone app?

No. The Solar iBoost+ does not connect to Wi-Fi and does not have a smartphone or cloud app. It communicates wirelessly with its Sender and can pair with the optional iBoost+ Buddy Monitor V2 for in-home monitoring and Boost control. If built-in Wi-Fi and app-based remote monitoring are important to you, consider the myenergi Eddi V2.1.

Does Solar iBoost+ need professional installation?

Yes. The Solar iBoost+ should be installed and commissioned by a suitably qualified electrician in accordance with Marlec’s installation instructions. Where technical after-sales support is required, enquiries should be directed to Marlec by the installer.

Downloads

Marlec Solar iBoost+ Brochure
Installation Guide – Solar iBoost+
User Manual – Solar iBoost+
Benefits of the Solar iBoost+
Solar iBoost+ Plus FAQs
Troubleshooting Guide

Video – Marlec Solar iBoost+ Plus Install Guide