As far as I know, Elektrobock can do this. This is a closed system and the head (valve actuators) are huge. Danfoss, on the other hand, has slim and elegant valve actuators. However, their technical documentation is full of marketing s**t with little information. It is so poorly written that it is impossible for me to guess whether their thermostat heads can start the boiler independently. Moreover, their central unit costs more than a fully-blown tablet PC with a very limited functionality. Closed system, no connection to the computer, no computer programming, closed data protocol (and they do not plan to release it). Hope this helps.
You're right the Danfoss system is quite expensive and uses for some reason a !@#$%^&* proprietary version of the Z-Wave protocol, but it can be useful to solve the problem of switching the boiler on/off when heat is needed in a particular room.
Have a look at the Danfoss Link system (here explained in Dutch: http://verwarming.danfoss.com/PCMPDF/Da ... FZC110.pdf
It uses the open Z-Wave radiator thermostats Living Connect, which can be controlled by 3rd party Z-Wave controllers. In the meanwhile the central control unit Link CC, the floor heating controller Link HC and room thermostat Link RS are closed Z-Wave devices.
This means you can switch the boiler for heating each room with a number of Living Connect radiator thermostats, and control them with your computer.
The floor heating however can only be controlled with the Link CC
Finding a solution for an open Z-Wave controlled floor and radiator heated system (with a boiler) is a quest I'm after for a looooong time now and there doesn't seem to be a real answer as long as companies like Danfoss keep their Z-Wave devices closed.
Let's keep hoping for an open future!