Viega Fonterra Smart Control is a great product, it’s actually the best system for floor heating I’ve ever seen:

• You never have to fine tune the flowmeters (it’s done automatically!)
• It constantly adjusts itself, this increases comfort and saves a lot of energy.
• It can be combined in a classic system (heater on >75C with radiators and floor on max. 40 degrees) or in a solely Low-temperature system in combination with alternative heat sources.
• Even when additional components fail (e.g. KNX or internet connection is lost) the system works autonomously.
• It’s a complete system, not only a distributor. Viega also has the tubes, connectors, etc. and is known to have the “Höchster Qualität Verbunden” which I have to admit is really true. They have the highest quality in tubes and connectors. It might be a bit more expensive than other vendors but it’s build to last… a long time.

To fully integrate the system into KNX I created three building blocks. This gives many new advantages:

• Operating mode or temperature setpoint can be set from a KNX touch sensor or Visualisation (e.g. QuadClient).
• Heating can be centrally shut down when on holiday or leaving the house (i.e. by using a ‘central off’ button or presence detection).
• A connection can be made to the heater or boiler (e.g. by using a Theben Opentherm KNX OT box) to ensure that the heater is going to heat xx% when there is a demand from the floor heating system.

I made the next three building blocks (Gira Homeserver Logic Baustein) and they are completely FREE!

• Get temperature (to get the actual and setpoint temperatures from the Viega system)
• Set temperature (to set the setpoint temperature)
• Set Operation Mode (to set the system in Comfort, Night, Leaving Home, Standby, etc. mode)

Alternatively you can also buy an ISE module which does basically the same, although it isn’t updated frequently and is really expensive! If you don’t have a Gira Homeserver or Gira X1 this might be worth looking at. If you own a Homeserver or X1, better spend your money on the real hardware (Viega pipes, connectors or an Opentherm box).

Download Gira Homeserver – Viega Fonterra Smart Building Blocks v1.2.zip

Download X1 Logic – work in progress, will be available soon!

Note: At this moment it isn’t possible to leave the Viega room thermostats out and push the actual temperature from a KNX room thermostat (most houses will have touch sensors with build-in temperature sensors already). In my opinion this is a big shortcoming so I contacted Viega and they gave me the opportunity to visit their office in Attendorn (Germany) to explain the need for this. To make a long story short: I have good faith this will be updated in the next version. So for now, you have to use the Viega room thermostats, but soon you’ll be able to just use your KNX touch sensors only.

Examples:

References

Set Operation Mode (BS: 13662)

Set Temperature (BS: 13661)

Get Temperature (BS: 13660)

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