Help in wiring for Vaillant EcoMax

Hello ,This is my first post here for help so please bear with me if this topic has already been discussed before

I have got Vaillant EcoMax 24k Combi boiler (no hot water tank )

I ahve bought a new wireless thermostat V3+,And my boiler or house dont have any kind of thermostat installed at the moment

Bit confused with wiring instructions from Tado so i am posting a picture of my boilers wiring and would appreciate if someone could put me in right direction about wiring

Tado auto instructions says i just need 3 core of the cable (out of 4 cores)and should ignore the black cable

and on the wireless reciever side i should make a loop between L and COMMON and the grey would go in CH NO

i am doubtfull about this wiring

can anyone suggest what i am suppose to do ?

I think gery and black cable should go in 3 and 4 at RT230V And then should go at Common and CH NO