CSST Gas Lines and Proper Bonding
by inspector_nick
CSST stands for Corrugated Stainless Steel Tubing. This is a flexible, stainless-steel gas line often covered in a yellow or black jacket. CSST is used to carry gas from the main supply (like the gas meter or propane tank) to appliances such as furnaces, hot water tanks, gas stoves, or gas fireplaces. Because it bends easily, the line can be routed through walls, ceilings, and crawlspaces more quickly than traditional black iron pipe. CSST has been used for many years, but bonding requirements became standard around 2006, so older homes may not meet today’s standards.
Why Bonding Is Important
Bonding is the process of connecting metal components of a home to the electrical grounding system. A bonding wire and clamp create a direct path for electricity to travel safely to the ground. This step is critical for CSST because nearby lightning strikes or electrical surges can energize metal components. If the tubing is not bonded, the electrical charge may travel through the thin stainless steel wall of the CSST and create tiny holes. This can lead to gas leaks, or in rare cases, fire or explosion. Even if your CSST was installed according to the code at the time your property was built, safety experts recommend upgrading the bonding to current standards to limit hazards and risks.
How Proper Bonding Works
A licensed electrician will install a bonding clamp at the point where the flexible CSST tubing connects to the rigid gas pipe. Bonding clamps and wires can be located inside or outside your home. A continuous copper bond wire should run from the clamp to your home’s main grounding system—often the ground rod near the electrical service panel. This connection ensures that any electrical energy is safely carried to the earth.
Signs Your CSST May Need Attention
- The flexible stainless-steel gas line is visible near the meter or appliances.
- There is no obvious bonding wire attached to the gas piping.
Note: Look for flexible tubing with a yellow or black protective jacket over corrugated stainless steel. CSST lines are usually longer. Your home may have shorter, flexible lines right at the appliance (like a gas stove), but these are not necessarily CSST, and they follow different safety rules.
What to do Next
If we identified that the CSST is not properly bonded, contact a licensed electrician and provide them with a copy of our inspection report. An electrician can complete or correct the bonding. If you need an electrician, check out my list of Trusted Partners.