Membership maintenance Customer not home during maintenance. Spoke to him on the phone to approve work done today. Checked all wiring and connections. Foot switch is glued down, making it on serviceable. Flushed and vacuumed condensate drain line. Evaporator coil, heavily impacted with dust and debris. Also found bacterial growth in evaporator coil. Drain pan. Change the customer supplied filter. Checked refrigerant pressures and temperatures and found system under charged. No history of leaks found on account. Subcool 3.1° delta T 13.4°. Spoke to the homeowner about these issues and he decided to move forward with the evaporator coil cleaning and adding refrigerant today. Performed a chemical evaporator coil cleaning. After cleaning the evaporator coil, I cleaned the evaporator coil, drain pan and added chemical to the drain line to ensure there are no clogs later. Added 1lb R410A to bring the system up to manufacture required 11° of sub cooling. The system is running well at this tim