Arrived at the home because of the Mr. Cool system wasn’t heating properly and going into defrost and staying in defrost for longer periods of time. I started looking at the system and noticed it was very frozen up, so I switched system form heating to cooling to defrost the System outside. Once I got all of the ice off of the system I started looking at the pressures and noticed the system was low on refrigerant. I charged the system with with 1 lb of 410a checked pressures and also checked performance and made sure the system was heating properly. The system is heating properly at this time.