s97

Vailant ecoTEC plus 637 System Boiler S Plan Unvented Cylinder Honeywell ST6400C controller 13 Radiators Boiler not igniting - S.97 F.75 Boiler was working fine before 2 radiators were relocated during renovation. Now boiler fails to ignite and gives s.97 then F.75 code. System has been...

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...