there is a loose connection at the rear of the freezer near or around the compressor unit , i strongly advise you to get a professional to look it.Regards
Haier are a bad brand, the unit has cooling fin frost up and will not allow air to pass through the cooling plates, defrost the unit for 2 days with door open and restart, if all good after that, keep doing it, if not, its lost gas and needs the bin. Quality items deliver lengthy trouble free operation, sorry but I put Haier in the Daewoo class, Kelvinator or Westinghouse next time, its worth that little extra. Regards Russ
Either way if you had the doors opened a lot, it should like you probably have frost build up preventing proper air flow. You'd need to pull everything out of the freezer and remove the lower back panel inside the freezer. If there is frost build up, you'll need to use a hair dryer to thaw all the frost out. The unit will continue to beep until the set temperature (0 and 38) are reached so that could take a while even after thawing out all the frost build up.
If removing panels sounds like more than you can handle, you can always unplug the unit for 24 hours and leave the doors open to allow the unit to defrost on it's own.
A Freezer usually has a condensor drain coming out of the compressor, that empties into a condensation dish underneeth, where condensation water is picked up and Re-evaporated.
It is most likely that your Drain is clogged.
Happened to me.
Have someone check your Drain, and if needed unclog it with a small prying tool into the tube.