Came out today to inspect a thermal zone ac system that is not cooling properly. Model #Tcfl-hm3621cc, serial #W231526540. Upon arrival the homeowner stated that the system just won’t keep up. I was able to see Paul’s notes and he added 2 lbs of 410-a and an ez seal stick on 5/22/22 and the homeowner hasn’t had any issues until recently. I called for ac at the thermostat and observed the system starting normally. The temperature split is at a 10° differential. I connected my gauges and noticed that the system is low on 410-a refrigerant. I presented the homeowner with a solution. I filled the system per manufacturer specs with 410-a refrigerant and added half a uv dye stick. Chud will return in approximately 4 weeks to perform a leak investigation. Performed preventative maintenance for a Lennox ac system. Model #C26-41fc-1, serial #5800F17588. Upon arrival I turned the thermostat off. I powered down the furnace and removed the access panels. The evaporator coils are clean and in go