Ecotec plus boiler with VR66 gives code s97

[coenvm]

I have mounted a VR66 wiring centre in dual zone (switch in position 0) with two VRT350 thermostats. The heater is an Vaillant Ecotec Plus with combiboiler from october 2020. And I must say it works very well when one or both thermostats ask for heat. When there is no demand for heat the boiler goes into a continuous test of the waterpressure sensor ( about 3 times per minute) and diagnose code s97 is displayed. At the moment there is a new demand for heat, the test stops and everything works fine.
When there is no VR66 connected and one VRT350 is connected directly to the boiler, it doesn't go into this testmode.
Does anyone has a clue?

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[Scott_D]

Think you might need to call vaillant tech for that one

 

[Aquarius]

From October, why not ask your installer? Could have left a link in perhaps?