Tado V3+ installation with district heating

[tu77e]

Hi all
Just got myself a v3+ stater kit to replace my honeywell thermostat and Honeywell ST699 programmer.
Before I replace the programmer, I noticed a couple extra wires in the existing connections so wanted to ask if I can just go ahead and reconnect the existing wires directly into the same connection on the tado programmer?

I can see that the HW COM loops to the CH COM which loops to the L, but there's also another brown wire in the HW COM which I'm not sure what for. Also have 2 wires in the N connection and not sure where the extra wire is going.

Can I just replace these all into the same slot in the tado and it should work as expected?
Thanks

 

[stem]

Inside the Honeywell you can see from the diagram you posted that there are two switches, one for hot water and one for heating. The Tado Extension Kit also has two switches inside. (Tado have different receivers / extension kits, but I believe yours will be as below, please post back details of it if not)

If it is as above, then from an electrical point of view you are swapping identical devices.

So as you have figured, provided that you keep the wires connected together exactly as they are now it will continue to work as it does now.

The above Tado Extension Kit has its connections to COM made internally so the links between Honeywell L, 5 and 8 can go, which will leave a lone brown wire currently in 8, that was connected to L by the links. This wire will need moving to Tado L.

Honeywell Heating NO (3) corresponds to Tado CH ON (4)
Honeywell Hot Water NO (6) corresponds to Tado HW ON (3)

However, you don't give any details of your existing Honeywell room thermostat, which would need to be set to its maximum setting to prevent it interfering with the Tado. If you want to remove the old thermostat, a wiring modification would be required, it can't just be disconnected. If it was just disconnected the heating wouldn't work.