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When was the last time this unit was serviced? This error usually indicated a dirty heat exchanger. Could also indicate clogged condensate drain if this is a condensing unit
Try powering it down wait a minute then power it back up. If that doesn't clear the error then you'll have to can for service. It could also be a faulty sensor in the heat exchanger which should be covered under the warranty
I'd suspect a bad sensor with a unit this new. There is one other possibility. Depending on the model if the air intake screen is blocked you could get this error. Make sure there's nothing obstructing the air flow around the unit. Beyond that you're going to need to call in a pro who can verify a warranty issue.