Chris Rosales and Derek came out to replace compressor due to short to grow on old unit. Place old 420 A in a tank and flushed the line set with acid flush and purged with nitrogen. Added line dryer to both sides of refrigerant and test for leaks, no leak and unit vacuumed down to below 500 microns. Test unit, added 14 0z of 410A to achieve subcool of 12. uNit is cooling at this time, will need to come back in one week to take out filter dryer and contaminated refrigerant.