M.B. Doc,
Many thanks for your support.
So, I will leave it as 10 and follow on testing the system.
Should the auxiliary w. pump intermittent error code come back I will test it with 2.
If the problema persists I will declare my pump as marginally good and decide if I simply live with it or try some brush cleaning or even replacement.
So far the AC is 99% Ok. This is a huge progress over the pre-coding, when the CCU itself was considered defective.
Best regards, Jorge
PS: MB ACs are very complex as compared to the vanilla AC solutions.