We had a Mitsubishi MXZ-4a36NA installed in our cabinet shop to condition four rooms. Each room has an indivdual indoor unit and each room has the same issue. We have had the Service Tech out several times in the past two summers but they have not been able to come up with a solution. Each unit is condensing on the wall side of the plastic housing and running moisture down the wall. The Tech checked the drains for pluggage and found no issues.
If anyone has seen this problem before or has a suggestion we will gladly have the Tech contact you. We have suggested this site but the Tech seems reluctant to presue the issue.
Thank you for your time.