Flexible gas lines

Inspected townhouse today that had flexible gas line running in from supply line outside house across unfinished basement ceiling through trusses all the way to furnace and water heater. I thought max was six feet for appliances, also had flexible line running back through ceiling to fireplace. Sent picture along to see. I’m assuming that all the townhouses in this association are done this way. This is Cottage Grove, MN maybe local codes differ here. I’ll check back later, thanks, Mark

That’s CSST.

CSST (Corrugated Stainless Steel Tubing). It’s designed to be the conduit for gas supply all over the house. What you’ve described is perfectly acceptable, provided it’s adequately secured and not exposed to sharp edges. Here’s a reference document.


Thank you very much gentlemen, I don’t see much of it here, just wanted to make sure.

If it’s yellow, it needs to be bonded…forgot to tell you that. You should see a copper electrode from the gas system to a ground–usually tied to a bus in the main panel box. The yellow CSST was involved in a lawsuit and bonding is required. Search this board for more info about the lawsuit. Here’s my comment about the lack of bonding:

“A common gas piping system called Corrugated Stainless Steel Tubing or CSST is present in this home. OmegaFlex’s product is known as “TRACPIPE” or “COUNTERSTRIKE,” Titeflex’s CSST product is known as “GASTITE,” Ward’s CSST product is known as “WARDFLEX,” and Parker Hannifin’s CSST product is known as “PARFLEX.” A lawsuit in 2005 claimed that CSST poses an unreasonable risk of fire due to lightning strikes. The lawsuit was settled and the manufacturers agreed to require additional electrical bonding above the minimum requirements set by the National Electric Code. We could not confirm that such bonding was present. You should consider a further evaluation and repair as deemed necessary by a competent, licensed electrician. More information regarding the suit is available on the internet here and here. A reference document is attached for your information.”

Also, another common defect: you’ll see it enter the furnace cabinet. it should be connected to a steel nipple outside the cabinet.

Thanks Joe!