Looking at the PDF file available here the new controller seems to have the standard layout with 6 terminals.
Neutral, Live, HW off, CH off, HW on, CH on.
So it should be easy enough to change.
Seems it has an extra function to old unit in that it releases the motorised valve when not in use. So the dip switches will need setting correctly for your system.
Most programmers can also be used with gravity domestic water heating systems as well as fully pumped and with the former it is not possible to have central heating without hot water and normally there is a turn buckle to change from 10 to 16 programs the latter only for systems with motorised valves.
Normally the instructions are good and if you get it wrong as to setting turn buckles they still work but some times not as expected.
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