Arrived onsite to investigate insufficient heat on a Lennox propane furnace. The unit had gone out the previous week but was operating properly upon arrival. I presented options to further diagnose the issue or to perform an annual tune-up. The customer chose to proceed with the annual tune-up as the first step. I explained that if any additional issues occur, further diagnosis may be required. Performed annual tune-up, cleaned the burners, heat exchanger, igniter, flame sensor, and condensate trap. Checked all safety controls, venting, fans, and overall furnace operation. Bubble-tested the gas line and checked carbon monoxide levels — no leaks detected. Verified operation; system is running properly at this time.
