Is My Condenser Defrost Running On A Timer? - Ask The Expert Episode 307

Today's question is from E.K.. "Hey Dan. Aren't all heat pumps defrost run by timer? My MRCOOL Universal will run defrost at intervals even if the coils aren't covered in frost. I'm in New Jersey for reference." Yes, but sometimes there may be frost accumulation that you can't see on the inside. Defrost mode kicks on because it needs to kick on. You don't want it to get completely covered in ice before the defrost turns on, because then your AC unit won't be working at max efficiency.