From what I can see you have the interface board and the cable and also two black wires from the connector block going I'm not sure where. I don't think it'll work correctly that way. If you go OT, whoever you chose disconnect the two black wires into the interface board and replace with the OT wires from your control. Then press and hold the hand symbol button on the right of the display until 'renote control' scrolls across the screen, the boiler then works OT. Do you have a normal digital display with temps, pressure etc?
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