Does anybody know what this message means? I have never seen it before. I checked the manual under troubleshooting and there was no mention of a message "Purify OFF! REVi" when the Service Light is Flashing. The DIG-220 unit is about 5 to 6 years old and the cell (RC-52) is about 2 to 3 three years old. Can anybody help me? I would be most grateful for any advise because I'm dead in the water (excuse the pun) right now. Thank you so much.