Wiring Tado Wireless Extension to zone valve of Worcester Bosch combi


Wondering if someone can help. I have:

1) A Worcester Bosch 550 combi

2) Four zones (two UFH, two rads)

One of my rad zones was previously on a “dumb” wireless thermostat. As far as I can tell, it is switched live.

I cannot work out how to wire the Tado Wireless Extension, and don’t want to blow anything up.

The first picture shows the old “dumb” wireless thermostat, the second shows the five wires that go to the zone valve, as they go into the wiring centre.

Many many thanks to anyone who can help