Performed annual tune-up on a propane furnace. Cleaned the burners, heat exchanger, igniter, flame sensor, pilot assembly. Checked all safety controls, air filter, venting, fans, and overall furnace operation. Bubble-tested the gas line and checked carbon monoxide levels — no leaks detected. The furnace is rusty, the A/C isn’t working and it’s 20 years old, I recommend replacing it. Verified operation; system is running properly at this time.