I purchased the I3 to fit in with our project which was to achieve Superhome status (superhomes.org.uk)
I would rate this product as excellent, but the 5 star is not possible as the set up was somewhat complex. The back up from Paul to setting up was excellent and managed to talk me through with out too much trouble. Mainly my lack of computer knowledge !!
We do not have a hot water cylinder so we are using the I3 to switch a heating element in a heat recovery unit and once satisfied to switch over to three towel rails with electric elements.
When monitoring the I3 either with the app or the portal it can be seen to respond very quickly to the varying solar output, keeping our export of electricity to a minimum.
For this project not only have we achieved the necessary Superhome status but the combination of the mechanical heat recovery and the towel rails operating through the I3 has helped eliminate the damp and black mould from the bathroom and en-suits.
The support from Paul in the proposed design was excellent, its not only the product but the support that sold it to us.

Haydon Edwards