Multiple Zone Smart heating upgrade - replacing four timers/zones

[neod]

Like many, I'm looking to move from dumb to smart but i seem to have an unusual starting point (rebuild about 10 years ago)
Current arrangement as below...

There is UFH with 4 room stats - 8 loops. I know this is independent of the other wall stat controlling the two sets of rads (upstairs and downstairs).
There are 4 programmers (timers) - 2 x ST9400s is potential fly in the ointment.
Thinking of the Wiser solution - e.g. Wiser Thermostat Kit 3
but how to replace both timers?

If it helps here's a pic of the wiring.

There are four motorised vales in all - two upstairs and two near the boiler (presumably HW and UFH)

TIA

 

[neod]

An update to the wiring centre - question is how to wire in (a smart controller) to address four zones? TIA

Also the HeatMiser

 

[BlueLoo]

Zero zone with a wiser hub and rad valves/ufh strips.

Every heat emiter gets a valve or switch.
These are all registered individually in the app and you control accordingly.

Your boiler bypass will need to be correct because you get the ability to lock out all valves. Easy enough.

Then you can control one emmiter or all of them at your will.

I do this. Works great.

You could/might argue that having the boiler on for just one room may be is a bit of a cycling load on the boiler but meh, I'd rather be using it than looking at it.

 

[neod]

Interesting suggestion. It happens I'm also looking (learning) at boiler modulation so this arrangement would be counter to that. Such is the joys of heating i guess. Will keep an open mind at this stage. Thanks.