21JAN2022 Jason B Arrived for fall tune up, spoke with Cheryl about the systems performance, no complaints. Cycle system on at thermostat then disconnect power at furnace. Pull blower and coil door, inspect heat exchanger, capacitor and blower motor. Reinstall blower pull and clean flame sensor. Test all pressure switches, then reconnect power. Cycle system on in heating. Adjust gas pressure to 1.8 and 3.5 IWC. Inspect HSI, burners, and all safeties. Check amp draws, inducer, gas manifold, temperature split, and CO Levels. System is running properly at this time. S=800 cfm needs 1400 R=1100 cfm needs 1400 (400cfm per ton of cooling) 4 ton system. Recommend we increase all existing ductwork and boot, or decide on rooms with the most trouble heating/cooling. This ductwork increase bid is to maximize efficiency of your existing equipment, not an emergency. Please call with any questions.