Perform Final Gas Leak Test

What happens here

Slowly open the main gas supply valve to allow gas to flow through the repaired lines. With the gas on, apply the soapy water solution generously to all repaired and reconnected joints, both external and internal. Carefully observe for any bubble formation. Even small, slow-forming bubbles indicate a leak that requires further tightening or re-sealing. This step ensures that all repairs are successful and the gas line is safe. Let the furnace run for a bit, then re-test all connections.

Goal: Re-open the gas supply and conduct a comprehensive final leak test on all connections using the soapy water solution.