Ac warranty service call. No cool. The technician found the system 3 pounds low on 410 A refrigerant. The technician installed 3 pounds of 410 A. The hvac has a 19 degree temperature split. I informed the customer to call back as soon as the ac starts to show signs of not cooling. The customer stated it’s been acting up since late February. We need to call the customer on Monday and set up a follow up in 2 weeks.