Warranty call On arrival unit has error code E3 limit switch open turn off the unit from breaker checked electrical connections checked limite switch connections found one of the limite switch tripped reset it turn the unit on checked electrical connections checked voltage and amps checked all other electrical connections in side the unit set unit to call for heat measured supply and return air it was high more the temp rise unit running for 2 minutes and the hole unit over heat and the error code E3 comes back checked the blower is over heat checked the burner over heat both limite switch tripped on this point I shut the unit off from breaker heat exchanger maybe cracked I tried to find any cracked I don’t see any find any cracked we have to come back when amana tech support when is open. unit is new we installed no payment collected is under warranty.