Suggestions for making heating and hot water smart

[golden root]

At the moment my heating and hot water are controlled via fairly normal looking Drayton programmable timers, but I'd like to replace them to make them both smart.

Ideally I guess I'd like to replace them with relays (one for hot water and one for heating) and have them switched on an off with automations in HA, as well as via buttons on my dashboard. I also have a few thermometers around the house, which I would want to roll into the automation for the heating (eg, if temp is below X at 6am, turn on the heating for an hour).

Can I use things like Shelly Relays for this purpose? Is there anything special about the heating and hot water 'on/off' switch that the existing Drayton unit manages? Is there a more appropriate solution to this problem?

Zigbee or Wifi would be preferred. Thanks.

(I am in the UK, if that is relevant)

[worn obsidian]

I've had a heat pump installed recently, they placed 2 shelly switches but I don't know how they're programmed

but the heat pump itself supports setting times for heating

[golden root]

Sadly, my boiler has nothing smart about it at all. Thinking about it a bit more, it's slightly more complicated that just a single switch, as when the heating is on, the boiler needs to be told to fire up and the heating value opened to let the hot water go around the radiators.