tethys energy


If you have an immersion cylinder with a heater element, why not use your PV solar panel system to heat your hot water?

The energy produced by the solar panel system during the day can be used to power your immersion heater giving you hot water without the need to turn on your boiler.

In doing this, you’ll save yet even more money on your energy bills as you’ll be  buying less electricity and also less gas (or oil) for your boiler. During the summer months you may find that you do not have to have your boiler on at all!



The Solar IBoost+ is brought to you by Marlec. It is an automatic water heating device for PV solar panel system owners, with over 45,000 products successfully working in UK homes.

How it works

1. Using just a single clamp installed at the household meter, the Sender transmits vital export energy to the Solar IBoost+ wirelessly.

2. Solar IBoost+ is activated when excess energy is available. It intelligently controls and adjusts the flow of energy to the immersion in proportion with the fluctuating export levels.

3. Water is heated during the day using excess energy only up to the immersion thermosstst’s setting. You can top up if required from usual heating methods or using the Solar IBoost’s grid power function.



  • Solar Iboost+ fits quickly and neatly next to your water cylinder wired simply between a fused spur and the immersion. No need to change your standard immersion heater up to 3kW.

  • It responds rapidly to the varying home consumption and changing weather ensuring that only excess power is used.

  • Solar Iboost + features connections for 2 immersions, switching between them automatically to maximise electric water heating systems.


  • Wireless Sender eliminates unsightly and costly wiring.

  • Solar Iboost+ displays real time information “Heating by Solar 1.6kW” and historical energy saving figures are seen at the push of a button.

  • LED’s also give an instant visual indication of the system in operation.

  • Simple programmable timer enables Solar Iboost+ to work in harmony with your existing water heating system on a 5/2 day basis. Even separate winter and summer settings can be programmed and switched between at the push of a button.

  • Built-in Boost override switch keeps you in control so you can top up your hot water in 15 minute increments up to 2 hours.

  • CE compliance to all product and safety standards conducted by independent test laboratiories.

  • 2 year warranty. Dimensions 288x255x100mm 1.95kg


To find more please give us a call 0118 3341 374 or email jason@tethys-energy.com

You can also contact us by filling out the contact form and someone will respond to you shortly.

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