That makes sense. If you follow the flow chart you’ll see the feed runs through rocker switch, through room stat, through control stat and linking off to diverter valve at same time which motors over. What was happening was there was no feed from room stat, so burner wasn’t igniting and diverter wasn’t motoring over, by manually moving the actuator you were switching end switch, which connected a permanent live to pump as well as opening up CH port, this in turn was circulating hot water already in system around radiators. I assumed you had tested room stat function some time ago when I posted screenshot, I didn’t take into account you were unsure how. You might be able to take PCB back and get a refund, however I would keep it as you might need it in the future.
