Horstmann H425 Timer Replaced with E7+ but not working

I have a Gledhill Pulsacoil III cylinder. Recently the Horstmann H425 timer stopped working and I hired an electrican I know well to replace it with a modern Secure Horstmann Electronic E7+ Hot Water Programmer (Gledhill confirmed this timer is compatible). He says he connected it up the same way as the previous old timer H425, which worked fine before the mechanism failed.

However I think he must have got something wrong, as the boost element works fine on the timer but the economy 7 element is not working at all. I can see this from the app. Both elements have been tested with a multimeter and are reading about 17-18 Ohms so they're ok (or at least either should both be working or failing). I have coloured the wires in thew photo to show how it's wired up.

Does anyone have any idea of what's wrong or a recommendation of someone around London very familiar with these timers who could likely repair it?

Hi, can anyone help advise?

Sach160 said:

He says he connected it up the same way as the previous old timer H425, which worked fine before the mechanism failed.

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That doesn't make sense it is a completely new timer so needs connecting as per the instructions for this unit.

Sach160 said:

However I think he must have got something wrong, as the boost element works fine on the timer but the economy 7 element is not working at all. I can see this from the app. Both elements have been tested with a multimeter and are reading about 17-18 Ohms so they're ok (or at least either should both be working or failing).

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Has the safety cut out on the off peak immersion been checked?

Sach160 said:

I have coloured the wires in thew photo to show how it's wired up.

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Cable runs do not show how it is wired up. If it is wired up correctly then who programmed the unit? The default times for off peak on this unit are between 2:15 am and 7:15 am. Check the settings for off peak on the unit that they are showing correctly (to the time period you have off peak). You could try a reset of the unit and re-program if it is still not working. Of course the unit could also be faulty on the off peak side.

Sach160 said:

Does anyone have any idea of what's wrong or a recommendation of someone around London very familiar with these timers who could likely repair it?

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