The Solar iBoost+ is a PV immersion controller which diverts excess energy to immersion in your water cylinder, allowing you to heat your water while saving on energy.

There are two key components of the Solar iBoost+ that help to convert the energy from your solar panels to your hot water system, the Sender and the Immersion controller.

The Sender is a wireless monitor attached between your electricity meter and consumer unit. It monitors the excess solar energy produced by your panels.

The Immersion controller receives that information. If you generate more solar energy than you consume then the Sender directs it to the Immersion heater.

The Solar iBoost Buddy is an optional device that allows you to track and manage your available excess electricity available in real time, meaning you are able to choose the most efficient and effective times to divert energy.

The Solar iBoost+ is a great way to cut costs and save energy. Some of the main benefits of installing an iBoost+ include lower water heating costs, reduced boiler usage, maximising the use of solar energy, and it’s environmentally friendly.

Two years. This is subject to proof of purchase and conditional on correct installation in line with our instructions.

The Solar iBoost+ automatically detects that there is no export taking place and stops heating water. It resumes when export is next detected and the built in memory retains the settings and savings to date.

The Solar iBoost+ can be powered down at the supply switch that your electrician has installed next to it, commonly in UK this was the immersion switch. It is recommended that the unit is powered down during periods of holiday or absence from the property.

Where there is a single phase supply at the property more than one Solar iBoost+ can be used to heat 2 separate cylinders. This is achieved by fitting a Solar iBoost+ at each cylinder and placing the Sender and Clamp as usual at the household meter and follow these instructions:

Ensure the clamps are separated by at least 10cm (3″) to avoid any inducted interference.

Set the cut-in threshold of one of the Solar iBoost+ main units to 50W or more above the other and this will operate as the secondary unit. The factory default cut-in threshold is 100W and this can be adjusted in 50W increments up to 500W maximum.

Solar iBoost+ is designed for use with up to 2 immersion heaters each rated up to 3kW for water heating in the home, each immersion is used in turn by the Solar iBoost+.

The immersions must have thermostat controls but no electronic controls between the Solar iBoost+ and the immersion. Take care not to connect any devices with any electronic controls as these and the Solar iBoost+ will be damaged. Solar iBoost+ installation should only be done by a qualified electrician.

The batteries in the Sender usually last between 1-2 years. When approaching depletion a warning symbol flashes red and the message Sender Battery Low appears on the Solar iBoost+ screen advising that the batteries will soon require replacement.

If you have an iBoost+ Buddy the signal strength and battery condition are permanently displayed. Rechargeable batteries are not suitable in the Sender.

A standard immersion element rated up to 3kW is suitable. As the immersion element is a resistive load it will accept any variable amounts of power up to its rated maximum.

This enables it to accept even the smallest amount of power sent to it from the Solar iBoost+ and start heating water. The Solar iBoost+ has connections for 2 separate immersion heaters, each can be rated up to 3kW and they will operate in turn to heat the water whether they are Heating by Solar or are in grid Timed or Boost modes.

Solar iBoost+ uses electronic control technology (pulse width modulation) to cleverly allow only the same as the excess power generated to be diverted rather than full power of the immersion.

As this excess energy varies, Solar iBoost+ manages the power levels applied to the immersion up to a maximum of 3kW. It is not an open and close switch.

The Solar iBoost+ version has a cascading load system. This means that 2 immersions can be connected, the first is the priority and when this is satisfied the excess solar energy transfers to the 2nd immersion.

A clever feature is that the system checks the condition of the 1st immersion every 15 minutes, if the temperature has fallen the excess solar energy reverts to it until it is again satisfied and then returns to the 2nd immersion.

This cycle continues until both are satisfied when Water Tank Hot is displayed. Once both immersions are satisfied the Solar iBoost+ enters a standstill period of 15 minutes before resuming water heating should it be possible.

Yes, a useful feature in Solar iBoost+ is the option to switch rapidly between Winter/Summer/OFF Timed settings.

This is useful if you want to use grid power to top up the free hot water but the duration and start time might be different according to the time of year and how you are using any other heating system.

Winter/Summer settings means that you only need to program the times in each season zone once. You can switch between Winter, Summer and Timed OFF by scrolling to the end of the Display button until “In Winter (or Summer) Boost” displays and simply pressing A button to change the setting. This feature is also selectable from the remote iBoost Buddy where used.

An example of when you might use this is: In the summer when your space heating is off you may want to switch off gas or oil water heating too if your Solar iBoost is delivering most of the hot water you need. You should note that grid power is used during the timed operations.

In winter you may not need the timed top up if your gas/oil heating is operating so your winter settings will be zero.

The Solar iBoost+ uses a special switching method to switch power into the immersion heater, this technology does not cause flicker on electrical circuits.

The Solar iBoost+ has a 100W export threshold before it starts to divert energy to the immersion. This smooths out any rapid changes in energy consumption and generation so that only on-site generation is consumed.

From April 2019 the Solar iBoost+ was released with a programmable function to raise the cut-in threshold, primarily this was introduced to accommodate some battery charging systems with thresholds around and above 100W. The homeowner can decide how to prioritise self consumption depending on the cut-in threshold of the particular battery system installed.

Battery Charging Prioritised – where the battery cut-in is <50W the Solar iBoost+ can be installed without adjustment. Where the battery cut-in is close to or more than 100W the we suggest a raise in the Solar iBoost+ a cut-in level of 50W higher to avoid any conflict in operation. Some battery systems send low levels of power to the grid when in operation which can be seen as export by the Solar iBoost+. Simply raise the Solar iBoost+ level in 50W increments until any conflict is overcome. We recommend that battery systems cut-in levels be set as low as possible if adjustable, to maximise self consumption.

Hot Water Prioritised – Set the battery charging cut-in level to >100W, maintain a gap of 50W between the settings if possible.

Note: Solar iBoost+ model prior to April 2019 are also compatible alongside battery systems with thresholds under 100W without any changes normally. For battery systems with a higher cut-in the Sender 250 is available on line to retro-fit in place of the existing Sender and cuts-in the Solar iBoost+ at 250W.

The Solar iBoost+ includes a programmable timer for 2 times each day on a 5/2 day basis. This feature can be used to replace existing timers. At the user pre-set times full grid power is diverted to the 1st then 2nd immersion independently of the PV generation.

The water may already be partially or fully heated from the day’s excess PV power and thus the grid operation may only need to “top up” the pre-heated water.

Yes, the Solar iBoost+ main unit has a “Boost” button. Each press of the button increases the time the grid heats the immersion by 15 minutes and can be set to run for up to 2 hours.

The time remaining counts down on the display but if the thermostat temperature is reached sooner it automatically switches off. If you add an iBoost+ Buddy then you can also press the Boost button remotely within the home. Find out more here:

Solar iBoost+ Manual

iBoost Buddy Manual

Approx. 50m line of sight, or up to 30m within a building. The strength of the signal can be affected by thick walls in a similar way to a wireless router or a cordless phone in your home.

In the unusual case where the signal is weakened a Clamp Cable Extension is available to purchase on line, this 5m cable can be used to run through walls to bring the Sender closer to the Solar iBoost+. The extension simply plugs between the Clamp and Sender.

The system operates using the radio frequency 868mHz.

The range of Solar iBoost is effective in most homes and experience to date has been good. A clamp cable extension is available to purchase that can be passed through thick walls to improve signal strength.

There are 2 possible options:

1. Use one Solar iBoost+ on one phase with its own 3kW immersion. The Sender, Clamp, and Solar iBoost+ must all operate on the same phase. In this case it is important to understand that excess energy measurement is taking place on that phase alone and others may be importing at a time when the selected phase is exporting.

2. Fit one Solar iBoost+ onto each phase, each with it’s own 3kW immersion on that phase. The excess on each phase is diverted individually.

Cables from the consumer unit to the switched fuse spur feed to the Solar iBoost+ input do not need to be dedicated. The cable from the Solar iBoost+ to the immersions must not be interrupted by any switches or timers, nor must the output be mixed with any other grid power supply.

The Solar iBoost+ must be connected exclusively to any immersion it is attached to or damage will occur. Solar iBoost+ should be installed by a qualified electrician. Read the manual carefully before proceeding to avoid damage at installation.

Solar iBoost is compatible with transformer, transformer-less and micro inverters and there is no interference between the two devices.

Installation should be arranged so that the cable from the Solar iBoost+ output to the immersions is no more than 3m long. For this reason, installation at the airing cupboard, hot press (in Ireland) or simply next to the hot water cylinder is recommended.

For safety reasons your qualified electrician will need to ensure that no other loads can be connected between the Solar iBoost+ and the immersion. Read the manual carefully before commencing installation.

Yes. The Solar iBoost+ has a 100W export threshold before it starts to divert energy to the immersion. This smooths out any rapid changes in energy consumption and generation so that only on-site generation is consumed.

From April 2019 the Solar iBoost+ was released with a programmable function to raise the cut-in threshold primarily to accommodate some battery charging systems with thresholds around and above 100W. The homeowner can decide how to prioritise self consumption depending on the cut-in threshold of the particular battery system installed.

Battery Charging Prioritised – where the battery cut-in is <50W the Solar iBoost+ can be installed without adjustment. Where the battery cut-in is close to or more than 100W the we suggest a raise in the Solar iBoost+ a cut-in level of 50W higher to avoid any conflict in operation. Some battery systems send low levels of power to the grid when in operation which can be seen as export by the Solar iBoost+. Simply raise the Solar iBoost+ level in 50W increments until any conflict is overcome. We recommend that battery systems cut-in levels be set as low as possible if adjustable, to maximise self consumption.

Hot Water Prioritised – Set the battery charging cut-in level to >100W, maintain a gap of 50W between the battery cut-in and Solar iBoost+ settings if possible.

Note: Solar iBoost+ and Solar iBoost (original) models prior to April 2019 are also compatible alongside battery systems with thresholds under 100W without any changes normally. For battery systems with a higher cut-in the Sender 250 is available on line to retro-fit in place of the existing Sender, this cuts-in the Solar iBoost+ at 250W.

The Sender and Clamp should be fitted at the household utility meter cabinet. Ensure the clamp’s latch is firmly closed around the live feed from the utility meter to the consumer unit.

A label on the clamp clearly indicates to the installer how to be sure of fitting it in the correct orientation. The clamp should be fitted on the utility meter side of a Henley block if present or the readings transmitted will not represent exports alone.

The Solar iBoost+ connects wirelessly with the optional iBoost+ Buddy. This is both a home energy monitor and remote display and control for the Solar iBoost+ giving you convenient and quick access to what’s happening with energy in your home.

The “eco-gauge” swings to indicate energy consumption or excess and a “traffic light” glows red/amber/ green to let you know if the home is importing and exporting energy.

As your PV solar array starts to generate in excess of your household power requirement the Solar iBoost+ will begin to “dump” energy into your hot water tank.

For example if you have 2.2kW of export energy then the Solar iBoost+ will divert this less a small buffer of up to 100W to ensure that the system deals smoothly with the changing use of household energy and the PV array’s generation.

The Solar iBoost+ main unit has a built in display, simply touch any button and the back light illuminates, if energy is flowing “Heating by Solar xx.xxkW” will display.

Each press of the Display button reveals savings from Today, Yesterday, Last 7 Days, Last 28 Days, Total Savings. You can also view this remotely within the home by adding an iBoost+ Buddy to the system.

This connects wirelessly and is also a home energy monitor that displays import and export levels. Find out more here:

Solar iBoost+ Manual

iBoost Buddy Manual

The Solar iBoost+ measures the export at your utility meter so if you regularly export power from your property the Solar iBoost+ will divert to the immersion. Wind turbines of high capacity can produce high levels of excess energy which may affect the life cycle of the product compared with a typical household PV solar system.

The clamp rapidly detects changes between import and export and sends a signal to the Solar iBoost+ to taper back any water heating to maintain minimum export levels.

If exports drop below 100W Solar iBoost+ switches off and waits until exports are restored and it returns to “Heating by Solar.”

If you have an iBoost Buddy fitted you will see the changes between import and export in the home and know when spare energy is available for use elsewhere.

In the UK Solar iBoost+ does not affect your FiT Generation payments. If in addition you have a “deemed usage” Export contract this remains unaffected and it is most beneficial to self consume all on-site generated electricity. Where an export meter is fitted the benefits of the Solar iBoost+ can still easily outweigh the rising energy costs of water heating.

Worldwide as well as in the UK Feed in Tariffs are reducing in favour of self consumption which is usually advantageous compared to using higher cost grid power.

Immersion heaters, sometimes referred to as “elements” must contain a thermostat, ask your electrician to test both of these before installing your new Solar iBoost+. When the set temperature is reached the thermostat operates to switch the element off.

The Solar iBoost+ automatically switches over to heat the 2nd immersion if connected and when the immersion(s) is/are satisfied ‘Water Tank HOT’ is displayed.

Immersion heaters have dedicated internal thermostats and are not affected by the thermostat usually found on the outside of a cylinder which controls other forms of heating such as gas or oil fired.

Only if you use the Boost or Programme functions. Boost gives instant energy to the immersion each press of the button adds 15 minutes to the time of operation for up to 2 hours. It heats until the thermostat switches off or time concludes. There is a built in programmable timer to use full grid power for water heating.

Only if you use the Boost or Programme functions. Boost gives instant energy to the immersion each press of the button adds 15 minutes to the time of operation for up to 2 hours. It heats until the thermostat switches off or time concludes. There is a built in programmable timer to use full grid power for water heating.