Do I need the extension kit and thermostat? Honeywell system.


HI, I am looking for some advice.

We want to replace the thermo stat with a Tado device. Don't need to control the hot water with Tado unless I have too. or its an easy swap out.

Below are photos of my system.

I have Worcester Greenstar HE condensing boiler and a cylinder in the airing cupboard.

Do I just need to replace the Thermostat, or do I need to get the extension kit and replace the timer?