The error code list for the VENTUS X are available for download below.
Extra codes in the unit not in the PDF:
"PP" means "Searching the router"
"SA" means "connected to the router"
"AP" means "connected to the server"
"CL" means "Net filters need to be cleaned"
"d3" means "water full protection"
"PA" means "Mode conflict" (to erased it put all units in only cool or only heat then disconect power for 20min)