Marlec iBoost install price?

Hey all, I’ve been quoted £650 to supply and install an iBoost solar diverter. I have no idea whether that’s a good price or not, has anyone installed one and know how much they paid?


Sounds a bit expensive - a MyEnergi Eddi is £400 and then maybe £100-150 for install - not a big job, just needs to put it where then mains comes in.

Agreed £650 for an iBoost sounds expensive and I’d rather have the MyEnergi Eddi anyway given the choice. I suppose if the iBoost has some added optional extras included in the price (eg wifi or ethernet connection and ToU optimisation / integration with other smart tech) then that might be OK; but those would normally be optional extras.

Thanks both, useful sense check.

I didn’t know about the MyEnergi Eddi.

I will do some actual research into the two options rather than just rushing ahead with the iboost :slight_smile:

Do you happen to know, can the MyEnergi Eddi do variable power control of the immersion?

Ours is a 3kW immersion and our PV is 3kW so we typically have 0.5-2.5kW “spare”, never the full 3kW.

Yes (as I understand it) the MyEnergi Eddi should be able to work in the way you need it to.
Obviously check with an electrician for the actual installation.
Oh and you may need the MyEnergi Harvi unit (as well, cost ~£50 if I recall correctly) to transmit data from your meter cupboard to the Eddi unit depending on the actual location of your immersion heater and cylinder. However, if the meter cupboard and cylinder are close enough together then a simple wired connection may be possible, ie omitting the Harvi wireless transmitter device.

Is that always the case? If the spur to the immersion heater passes close, then is the proximity to the actual immersion heater important? I currently have a smart switch by my distribution board.

I am not sure but I think the iBoost or the Eddi will also need a feed temperature direct off the cylinder in order to know when to stop feeding elec into it. Other configurations with all the control electronics located in the meter cupboard may be possible but obviously you would need to get that checked out by the installer / electrician at the time.

As long as the thing you are heating has a thermostat then it will automatically stop drawing power when in reaches temperature and the Eddi will see this and stop drawing power too. So the only connection you need between the Eddi and the tank is the electric cable.


All done and dusted now, quick follow on for any future readers:

I queried the breakdown of the £650 quote and the electrician was factoring in a big margin for uncertainty because he hadn’t seen the existing wiring etc. Furthermore, I had requested:

  1. The iBoost needed installing alongside the ShellyEM relay from the Powershaper trial, and
  2. Could he please inspect & rectify any issues with my self-installed loft consumer unit and new immersion circuit…

We agreed to make it an open invoice between £450 and £650 depending on what rectification needed doing.

He did the job on Saturday and was great. He approved of my wiring! :smiley: Really nice to get it all inspected.

The final price was £450 for the iBoost and installation.

Regarding the variable power output, the iBoost measures the export and powers the immersion with modulated DC. It aims to match the export power -100W so if you’re exporting 1kW it tries to put 900W into the immersion. It reacts fairly quickly: if I watch the display it’ll jump around as clouds go overhead / appliances turn on and off.

Thanks for the input everyone. Paul