Got this reply from Horstmann:
Thank you for your enquiry, the E7bx unit works off 2 inputs one is available 24 hrs a day where the other is only available during economy times set by your energy supplier. Where as the Electronic 7 (Digital display) works with only one power input and the...
As per the title. I’m looking to get a bit more control over when I want the hot water boosting etc & the Hoffmann Electronic 7 looked to be an ideal solution.
However when doing a bit of reading it appears that I can’t use it as a replacement for the E7BX.
Is there an alternative that I can use?