If you are installing a new gas appliance, or you have an old appliance that hasn’t been serviced in years, replacing the flexible gas connector will help to avoid a dangerous gas leak.

Step 1: Flexible stainless steel gas connectors have been the standard in appliance installation since 2006. To determine whether the existing flex line is code compliant, look for “ANSI Z 21.24” stamped on the connecting end of the line. Most compliant flexible gas connectors are yellow or uncoated stainless steel. Gray or uncoated brass flexible connectors should be replaced immediately.

Step 2: Do not reuse flexible lines, fittings or valves, even if they are new. Gas line fittings are designed for one-time use only. Disconnecting a previously tightened fitting can damage the connector and make the seal unsafe. Purchase a flexible gas connector long enough to allow the appliance to be pulled away from the wall if necessary and large enough to meet the BTU requirements for the appliance.

Many new flexible connectors now include excess flow valves. In the event of a gas line rupture or compromised connection, these valves reduce the flow of gas to a nonhazardous level. Choose a flexible gas connector with an excess flow valve.

Step 3: Use the nearby shut-off valve to turn off the gas supply. If there is not a shut-off valve in the vicinity of the appliance, the main valve will need to be turned off, and a proper shut-off valve should be installed.

Step 4: Remove the old flex connector and any additional fittings to expose the standard pipe threads on both the incoming gas line and appliance side of the connection.

Step 5: Clean the newly exposed pipe threads with a wire brush and rag.

Step 6: Apply gas-line-approved yellow thread sealant to the pipe threads. Do not apply sealant to flare-type fittings.

Step 7: Remove the fittings on either end of the flexible gas connector and thread them onto the exposed-thread seal-coated pipe threads. Use an adjustable wrench to tighten the fittings into place.

Step 8: Thread the flare nuts of the gas connector onto the newly installed fittings. Tighten the nuts into place with an adjustable wrench.

Step 9: Turn the gas back on and leak-test all connections with a leak-detection fluid before lighting any pilot lights or turning on any gas appliance.