Hi, hope that someone can shed some light on this please....
I have a full Vaillant system (ecoTec plus 624, VR66, VRC430f, Unistor cyl) but the Unistor has a thermostat not the VR10 NTC sensor.
I changed the stat over to the VR10- depowered, disconnected the stat at the VR66, wired the...