My air conditioning failed on me some time today when I was at work, and when I returned home it was 92° inside my home. Figures this would happen during the (hopefully) hottest week of the year in Los Angeles. This system was professionally installed in June of 2020, and has worked without issue until now. The company that did it was bought out by another larger firm, and they are unable to send a tech out for another 17 days. I’m kind of SOL there. I change the filters every six months in the air handlers, and regularly hose down/clean the exterior unit. With a basic visual inspection, it does not appear that there are any blockages/impediments to air flow. I have tried powering off both the exterior unit and both interior air handlers by switching off the breakers on two separate occasions. The cooling works for about 10 minutes and then the error message is displayed again on the interior control panel. Any ideas?

DAIKIN 20kw ducted system is throwing a U1 fault code.

We did change the power and incorrectly orientated the phases but have rectified this issue but we can’t clear the code to restart the unit.

I have continuity checked all the fuses on the PCB’s and carried out numerous power off resets including one over night but the fault code persist.

I think the indoor controller is just telling the out door unit it has a problem at this point.

Have cleared the fault off the remote but the out door unit still won’t start.

PCB’s don’t have any visible issues.

Any ideas on what to try next?? We really need this thing going as it’s being used for temperature control in a factory.