ESC was called out again to inspect the chiller as it was showing the same problem as before. This time when started one fan came on (this is not what happened last time) but the fan controlled by the VFD did not. It was eventually traced to a relay that has been replaced. The system was tested as best it could without a load and appears to be working. It will be difficult to tell until a heat load is in place if the fix has solved everything.