Nat Gas water heater electr. bonding

Looking at a brand new construction; nat. gas-fired water heater; there are no jumpers bonding hot and cold water pipers, nor to steel nat gas supply line; Acknowledging that there are probably already hidden areas within and outside home that bond nat. gas pipes to water…but much of interior plumbing is PVC.

  1. Can anybody cite any code requiring bonding for gas water heater?
  2. I am recommending bonding of hot and cold to nat. gas steel supply line.
    Does code support me on this? (If for no other reason, I’d rather be safe than sorry, especially since it’s maybe $10 worth of electr. clamps and a few feet of copper wire.)
  3. Acknowledging that dissimilar metal connections for water pipes is a no-no for galvanic corrosion reasons…but what about dissimilar metals for GAS piping? If plastic/nylon bushings are used to connect gas lines, such as at shutoff valve serving water heater, should that not also require a bonding jumper across these connections?
    Thanks, Gurus!

This is definately a requirement in Canada. The gas line must be bonded to the service grounding electrode.

Why you might not see ‘bonding’ is because of this. The NEC code requires piping that could become energized to be protected with bonding. So the idea is what could energize it, this case a water heater, can also bonded at the same time, with that circuit’s Equipment Grounding Conductor.

So if the water heater is properly installed and the EGC is bonded to it, its hot water, gas line, ‘grounded’ by many AHJ’s. The AHJ that require exterior bonding, “jumper cables”, are enforcing rules that prevent isolated piping should a component be removed for maintenance.

Ok for the code: 2005 NEC 250.104 is a good read.

all imho,


P.S. I ensure either the piping is grounded with the GEC on the way to the water main, or I run a seperate, properly sized bonding cable to to metal piping(such as gas) from the panel.

Thanks guys!
My guess is that if client expresses concern to builder about nat gas to water pipe bonding, the builder would reply: “No prob…we’ve already got that covered…” (by means of jumpers across water meters, exterior gas lines, and in other ‘hidden’ places. Which likely is true…if he’s a good, conscientious builder.
But me, being the “show me” sorta guy, if it were my home, for just a few dollars, I’d rather be safe than sorry, and actually be able to see that all water and gas pipes are bonded in this closet housing flammable vapors.


As Tom stated the EGC of a water heater that happens to have a circuit to it for ignition can be used in the bondingo of the unit itself…like in the example of a gas cooktop with an ignitor and a 120V ignitor receptacle…

However in 250.104 makes it very clear that if their is question to the reliable interconnecton of these lines ( hot and cold lines ) that they need to be bonded together with a bonding jumper.

I have been one of those who do not believe running the bond to the cold only line at the water heater is enough…I always jump them over and bond the both…

now the AHJ has a large call on this because if they can’t see where the lines run in the house they may not envoke the " likely to become energized" and thus not require it…however that 'Likely" only applies to the gas lines and OTHER piping…so bonding the metal water piping is a different story and should be bonded properly…

Personally I like to jump the cold to the hot…we are talking about only a 1" of less piece of # 4 CU in most cases…and ensures the bond is reliable.

As for “likely to become energized” as it pertains to GAS Lines…check out this example :

Bonding attachments are required to be accessible.

If the interior water lines are “PVC” (more likely they are CPVC), or other non-metallic piping, you will not find (nor will it be required) bonding of the piping at the water heater.

The gas lines will typically have the bonding wire visible near the gas meter.

Agree 100% with the POPE…much of our examples are for learning purposes…and dealing with Metal piping and so on…but if indeed it appears the majority of your plumping lines are CPVC or PEX and so on…you would not have to bond in accordance…

If the piping to the water heater is copper and it disappears into the wall…then I would bond it…better safe than sorry…if the water pipe comes in and its metal…you are required to GROUND to it…so this begin the terminology mystery of Grounding and Bonding…lol…2002 NEC has come a long way in clarrifying those terms…thank goodness.

IN regards to the bonding at the gas line…I rarely see them at the outside meter in my local situations…usually I see tracer wire their but not the actual bonding wires…go figure…but it is done all the time and fine.

Thanks, Paul!! I wuz hoping you would respond, as you be da man.
I think we’re on the same page here.
I personally want to be able to actually see bond to both hot and cold, AND to gas line in such a gas heater closet.
For just a few bucks, why take any chances in a closet with flammable vapors, huh?
Thanks again!

I must remind everyone that when in Rome, do as the Romans.

All of this is dependet on which version of the CODE your state requires. Here in NY, bonding H&C water pipes is not required, nor is bonding a gas line to ground. n fact, of Consolidated Edison’s inspectors (they are the actual AHJ) for NY City and surrounding burroughs, they will shut the gas of to the dwelling.

Also, here in NY, arc faults are also not required.

So, it is more than being familiar with current Code requirements; you must be up on the Codes which are IN EFFECT in your area.

If the local AHJ does not require it, or if an older version of the code has been adopted in your state, you can suggest these improvements as a recomendation, subject to olocal AHJ interpretation, necessity, and enforcement.

Ah…but I remind the ROMANS…if I can save their life because they just happen to still be living in the STONE ages…I will do it…:slight_smile:

All you guys in New York area live in the stone ages…lol…

No actually…if I was doing electrical ANYWHERE my training and experience would always lead me above the NEC standards because that is just how I wire homes…

But alas…bonding is a critical point for safety within a dwelling even if some areas simply do not see the LIGHT so to speak about the safety…but Joe F is right…lol…call me NewFasion…:)…I like seeing things BONDED even if above and beyond the call of duty…

However as HI’s…you are just observing this condition…but for added safety never wrong to suggest anything that in your mind you feel is an enhancement…regardless of CODE…ahh…that freakin CODE…lol

And Paul, if you bond a gas line in Westchester, Bronx, Brooklyn, NY City, or Queens county, the AHJ will flag it and shut the gas of to the house.

I believe the engineers of Con Ed also know a thing or two about power, grounding, and bonding. Perhaps, in their experience, there are circumstances where they do not want to see it. In our instance, they dont want to see it at all. Same here in Rockland, where Orange and Rockland Utilities make the rules…

Right, wrong, or indifferent, it is dangerous territory when the HI starts spouting electrical or plumbing code as Gospel, because sometimes, the “rule” as they know it may not apply.

Observe, report, and suggest things. Dont quote code.

lol…no one quoted code…lol…man…you jolly elf…:)…the original poster i believe was simply concerned on the bonding issue of gas lines and so on.

Hell in our area…if you dont bond it…you will be red flagged…so I have come to the conclussion…none of them know anything…:slight_smile:

P.S…education fella…only using CODE sometimes to define the understanding of the response…:)…I am 100% sure thats all tom used the CODE for…:slight_smile:

Oh yes, oh Guru of the Volt…:neutral:



lol…now stop…you are hurting my feelings…I may run away…:wink:

Just curious, how do you how that the hot and cold water water lines, and gas line are bonded correctly if the ground wire is terminated (cut on both ends) in the water heater closet of a condo? This particular inspection was an older condo complex and the water heater was a newer install. Clamps and ground wire connecting all three piping, but the wire did not lead back to the panel. Is this still properly bonded? Correct me if my terminology is incorrect.

A bond is simply tying different items together so they are at the same potential. It does not need to go to the panel. A gas water heater is considered bonded by its connection to the EGC in the circuit conductors.

Thanks Jim Port! Wasn’t quite clear with this, because I only have access to the interior of the condo, not to the whole building. Therefore, how would I know if this has been properly bonded. Look good in the closet, but would you reference to the HOA for proper bonding/ground or have the buyer consult a licensed electrician to trace it? Or am I over doing it?

The NEC doesn’t specifically require a bonding jumper as you have mentioned from the hot-cold-gas piping.

You have the hot, cold and gas bonded. There really is nothing more and it sounds above code already.

Grounding is another purpose and entirely different than he bonds.