Downstairs system, line set approximately only 15feet, during heat mode the discharge pressure increased over 500psi with suction of 150psi. Tech removed approximately 3lbs of refrigerant and managed to acquire normal operating pressures in heat mode, home heated from 53 degrees to 70 degrees with just the 2 stage heat pump. Tech switch it to cool mode and acquired not accurate readings due to the outdoor temperature not helping much, tech removed the air handler doors and to inspect the TXV to make sure the bulb was secured. Tech noticed that the sub cool of 2 degrees in cool mode did not move. System appears to be with proper refrigerant levels in heat mode but low on charge in cool mode, a follow up visit would be ideal on a warmer day to confirm proper indoor TXV operation, although the system does have a 18 degree delta T in cool, it does not confirm that the Indoor TXv is properly operating or non-condensible in the system are present. Tech will speak with our office about the fi