Mitsubishi Heavy Industries SRK 63 ZE S1 motor and PCB failure

[UNIPLAS]

Hi, I am new to RE and this is my first post so bear with me. I am seeking comments and advice. I look after 17 SRK 63 ZE S1 split units in a Church building (including Chapel, hall and meeting room). These units are used for heating the building. The units perform very well but the maintenance costs are incredibly high. There is common fault and that is the failure of the outdoor unit fan motor. On average there is a failure rate of one unit every 2 - 3 month and is common across all the units. I have been advised as well as changing the motor, the (main)PCB has to be changed. To the church the reoccurring cost of repair is unacceptable. It's worth noting that for the the first three years there were no motor failures. I would like to ask the forum if they have experienced this problem? Or should the Church accept this rate of failure? Any advice would be welcome.
Thank you