Ventilate Message

Every day I try to use my Saeco Royal Exclusive I get the ''Ventilate'' message. I run water through the hot water wand and it will eventually clear. If I let the machine set for 20-30 minutes I have to start all over again - it says ventilate. I've replaced the pump and the flow control valve. I've ran through 3-4 descaling processes with no better results.

Anyone got any clues for what else I can do?

I've read about doing a factory reset. Can someone tell me how to do that, I don't see instructions in the manual.