I see metal gas line bonded to the copper water lines near the water heater in instances where all the water piping (entry and distribution) is copper but;
1-How do you achieve bonding of a metal gas line if the water service entry piping is plastic?
2- How do you achieve bonding of a metal gas line if the water service entry piping is copper but all the water distribution lines are plastic?

Either bonding back to the panel or to ground rod(s) or other bonded metal in the structure.
Keep in mind:

Bonding of Electrically Conductive Materials and Other Equipment. Normally non–current-carrying elec- trically conductive materials that are likely to become energized shall be connected together and to the electri- cal supply source in a manner that establishes an effec- tive ground-fault current path.

Key here is likely to become energized. Unless of course there is CSST and bonding of the gas piping is a manufacturer requirement.


Bonding isn’t the same as grounding. Bonding provides a low impedance path to conduct faults back to the source so the OCPD can trip.

It doesn’t matter what material the service pipe is. If the distribution pipes are metal, and likely to be energized, they need to be bonded.

If the service pipe is metal and likely to be energized it needs to be bonded as well.

Plastic piping cannot be electrically bonded. It sounds like you’re confusing what the requirements actually are.

Gas piping does not require bonding to the water piping. Instead, all metallic piping (having the ability to become energized) must be bonded to the grounding electrode. Often you will find that copper (or other metallic) water piping is used to establish the bond for gas piping, but this cannot be achieved when the water piping is plastic.

In such instances, the gas piping should be bonded directly to the service equipment or the GE.

To add to what Jeff stated as well, In reality we have (5) locations that metal piping systems can be connected to within a dwelling ( or any building really). The grounding electrode is only one of those options. You still have four others so I will list them all below as written in the NEC for reference.

(1) Equipment grounding conductor for the circuit that is likely to energize the piping
(2) Service equipment enclosure
(3) Grounded conductor at the service
(4) Grounding electrode conductor, if of sufficient size
(5) One or more grounding electrodes used

This was basically the same as in the 2011 NEC but it was structured in a way that was easier to understand by giving it an item format.

The next logical change should have been to do the same thing to 250.104(A)(1) but it was not proposed.

My first question would be what type of gas pipe? Black pipe requires no bonding other than the EGC in the branch circuit supplying a gas appliance.

Obviously plastic piping cannot be bonded or grounded.
What I see when the ESA has done an inspection is that if the gas and water lines are metal there is a bonding wire is in place from the copper water line to the metal gas line usually above the water heater achieving the bonding. My question is if the water service is plastic how/where do you bond the metal gas line. I assume it is as Juan said that that the gas line needs to be bonded, so where do I look to see if that bonding is in place.

The bonding for the gas line can be in with the branch circuit wiring done with the egc.

Any other externally bonds could take place at a convenient location.

This bond is acceptable for all connected gas lines? And is a flexible appliance connector considered an interruption of that bond or does it adequately preserve the path?

All that’s required by the NEC is using the EGC within the circuit to the gas appliance. Flexible connections require no further bonding to ensure continuity.

Bonding CSST to mitigate lightning incidents is not covered by the NEC.

This is SOOOOO very important to realize…Glad Robert pointed that out. I sat on a task group for CSST and it was like watching pitbulls fight over this exact statement…the NEC stands behind 250.104 and we will leave the bonding by the manufacturers direction to the IFGC and IRC…lol

Yes from what I’ve read the NFPA wouldn’t accept the manufacturers recommendation for a #6 AWG bonding jumper to the CSST to solve the problem without some valid documentation.

Just a side note, bonding CSST does not occur on the flex itself.

yes, I was actually at the Redondo Beach NFPA meeting where this was being discussed and a presentation by Ms. Porter who sits on CMP 5 gave her opinion of the CSST and bonding per the manufacturer. Needless to say the CMP had more faith in what Ms. Porter said than the manufacturers of CSST or it’s cousin (still CSST) Counter-Strike…:wink:

Ironically many do not understand that and damage the CSST by trying to place a clamp on it(incorrectly mind you)…could be a disastrous moment…Thats the problem and why it brings up a argument point for electrician versus plumbers and gas fitters.

Who’s responsibility is it to make the connections per the manufacturer. My position is that it’s the installer of the CSST…but are they really qualified to make that connection…do they even understand the principles of the connection they are being asked to make…well you get my drift.

Do they understand that the connection is NOT to be made directly to the Corrugated Stainless Steel Tubing [CSST]…well…at this point the jury is still out on the “IF” they know…

So who do YOU trust to make the manufacturers required connection…Electrician, Plumber or Gas Fitter?

Maybe the NEC needs to clear that up.:wink:

Not our job…;)… we feel (I speak for the NEC today…lol) that 250.104 is clear and anything else is outside of the scope of the NEC…let the IGCC and IRC handle there part:twisted:

Interesting if the CSST would fail for not being bonded who gets the violation?

Do you mean when the house blows up? The** home inspector** that missed it. :twisted:

I think this is where the licensed electrician gets the “RUB”. When it is failed most of the time the electrician gets the “red tag”. However, they had nothing to do with the installation.

In the jurisdiction where I was the AHJ, the “red tag” went to whom ever installed the CSST systems. So in 99.999 % of the cases (ok 100%) it went to the plumber since they installed the CSST.

But your intended point is WELL taken and is true…many times it falls back on to the electrician and sadly the majority of them do not know how to terminate it themselves. They know to run the 6 AWG CU only to get confused how to terminate it since they are familiar with clamps on pipes…then they incorrectly try to clamp it to the CSST…and well…we know what happens next.

The installation guidelines from the manufacturer of the CSST is given (hopefully) to the CSST installer but sadly it never makes it to the Electrician who has to clean up the mess when a “Red Tag” is used in many states.