Sorry for not getting back to you soon but I have been trying to get some tech info on this control board.
Unfortunately I have had no luck.
I did find the tech sheet, see the attachment.
But it does not say how it calculates when to start a defrost cycle. It says a cycle every 6 - 96 hours of compressor run time. This is an inverter driven driven compressor so it is basically on all the time but varies the speed so they must be monitoring this speed or using info from the door open/close.
I just do not know.
I did notice that the boer wiring diagram does show a jumper for ADC (automatic defrost control) or timer. If your board has this, perhaps try shorting across it. The unit then should defrost a a set interval time.
Again I could not find any info on what that time would be.
Defective boards out of the box is a possibility but it is very, very rare that you would get a board that has the exact same fault as the one you replaced.
Just to recap the current status.
You can manually force a defrost.
After the ice/frost is melted off the evaporator coils the unit will run correctly until the ice/frost build up on the coils again to the point that the fan cannot pull air through them.
Then your temperature start to rise.
Is the above correct?
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