Using esm-esp with a Worcester Bosch boiler

Hardware
1

I have just installed an esm-esp on my Home Assistant. I have a Worcester Bosch Greenstar 25Si boiler with a RF562 wireless thermostat.

I’m looking for a bit of help working out which entities I should be trying to automate.

The only one I have successfully seen change on the boiler is “dhw comfort”, to change hot water from preheated to eco mode.
Tried heating_activated, but this turns itself back on immediately
Tried select_flow_temperature - has no effect on the boiler, tried with various configurations of thermostat active/inactive, timed/off/on/once etc

Hoping someone else might have done a similar setup and know what I need to do. At a minimum I’d just like to be able to turn it on and off, but anything more advanced is of interest.

2

What I think I might need is a new thermostat so the connection can go Gateway → Thermostat → Boiler, as it is I don’t think the gateway is capable of controlling the boiler with EMS 1.0.

Not 100% sure but that’s where my research is leading me.