Wiring from an old ideal icos 24 he to glow worm energy r25

[DG1878]

Struggling with wiring from an old ideal icos 24 he to a new glow worm energy r25. First photo is how the original boiler was wired in with your standard L, E, N, SL. But the new boiler if wired in that order with SL in RT just idles and the pump runs continuously.

System has underfloor heating and 1 zone valve with a one channel programmer for it. Orange from zone valve goes in with the live from the pump in the wiring centre then looks to link across to a switch live in the wiring centre. But where that black switch live goes I don’t know?

Zone valve stays open all the time even with programmer is turned off and pump runs.

Thought I could just copy the cabling from the last install as I wasn’t changing any external components however this doesn’t seem to be the case. Must’ve been an old switch live type system.

Am a gas safe registered engineer. Just not the greatest with the electrics side of things when it goes this deep.
Any help would be appreciated