Recommendations for floor heating system

[DaveFX]

Hi everyone.

My home is equipped with a 28-year old water underfloor heating system, with one heating distributor in each of the 3 managed floors, with 2, 5 and 2 circuits, respectively.

The water heating is currently carried out by a Vaillant gas-powered boiler, controlled through its proprietary modulating thermostat, which also operates over one single water pump installed inside the boiler.

At this moment, the underfloor heating system has no automated control of any kind. I have one master manual regulator for every floor, and every circuit has its own manual valve. As you can suppose, the regulation of the whole system is really difficult.

Looking for alternatives to improve the system I've discovered HomeMatic IP. I'm thinking about purchasing one FALMOT-C12 system, controlled through a CCU-3, and operating 9 VDMOT valve controllers, with their corresponding 9 HmIP-WTH-B thermostats to monitor the temperature of the rooms. I would use a WHS2 to control the boiler/pump activation and deactivation.

I would place the FALMOT-C12 in the middle-floor heating distributor, and I plan using extender wires in order to allow it to reach the VDMOT valve controllers in the bottom and top floors. Is this possible? Which kind of connector do they use? Is it a standard RJ-9 connector? How long can this wire can be at maximum? The wires between the first and second floor heating distributors could be about 10 meters...

Thanks everyone.

[Parafraseer]

Whs-2 cannot modulate. It is on-off only.
It is a standard rj9 connector. No experience on the length.

[DaveFX]

Modulating isn't a must for me. In fact, I recently discovered that the thermostat wasn't configured in modulating mode...

How long are the included connecting wires in VDMOT units?

Thanks for your answer!

[Parafraseer]

90cm