Hello! This is my first post so bear with me. I am trying to troubleshoot a FX20 that seems to be having a chiller problem. I am also jumping into the middle of this issue so I am playing a bit of catch up, again bear with me.

We have a FX20 EDM that seems to be having a problem with it's chiller. Unfortunately I have no manual for the chiller. What happens is that we get an "E1" error on the chiller control board and it is an un-resettable error... the machine needs to be powered down and restarted. This error is so erratic, at times the machine will run for hours and then it will trip every 5 minutes. Yesterday I sat with the operator of the machine and watched the display (as I understand showing the differential between the ambient air and the water) it was bouncing between .2 to .3 but never more than that and then it came up with the "E1" error and shut down. I would have expected to see a ramp up to the 5 degree trip point.

A call to Mitsubishi tech support came with an over the phone condemnation of the chiller and a comment about how there are no parts available. What they had us do was disconnect the chiller compressor from the VFD and run a test part for 1.5 hrs. We did that with no issues. Then they wanted us to reconnect and try running normal. Of course the water was too hot to do that test as we had a constant "5.F" error... but I am guessing that when I do get to run normal again it fails.

Anyone have any ideas? Any way to test the controller board? The model of the chiller is "Unit cooler, HE-UV3". At this moment I have no documentation on it.