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Bonding the Hot and Cold of a Water Heater

jar546

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We all know that this is a touchy subject. That is why I would like to discuss it here. There are a lot of viewpoints on this and I have come across many electricians and inspectors that differ in opinions on this subject.

There is no need to comment that you only see PEX these days, we are talking about copper piping systems, key word systems and the need for the system to be bonded.

My personal thought is that if there is a metal mixing valve installed in the system (crimped/soldered) then there is no need for a bond across the hot and cold. Most, if not all water heaters come with dielectric fittings making bonding across the hot and cold a requirement when the water piping system is broken into two areas, hot and cold.

Will you find a code section that tells you to specifically bond the hot and cold? No there is not. There is a requirement, however to bond the system.

Some don't understand, some do and some just do because it was always done that way. What is your opinion on this subject? Do you require it in your town and why / why not?
 
We require it, based on your premise. In our thinking, (my senior electrical inspector) all piping must be bonded. And you can not depend on a valve downstream to accomplish that.
 
Where is the requirement found to bond metal water pipes in or on a building? A- 250.104

How many ends are there to a bonding conductor? A- two

Where is the requirement for this bonding jumper required to end? A- 250.104(A) (last sentence) The points of attachment of the bonding jumper(s) shall be accessible.

Now that the point of attachment to the pipe has been established where is the other end of this conductor “required” to land? A- 250.104(A) (1) SHALL be bonded to the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where of sufficient size, or to the one or more grounding electrodes used.

If one is going to call the metal piping of a building two different systems such as hot and cold then each system is required to be bonded to one of the four places outlined in the section that requires the bonding. From one pipe to another pipe is not outlined in that section.

Also if we are going to be connecting these pipes to a kitchen sink then we must follow the plumbing codes which only allows for one piping system to be connected to this mixing valve and it will be potable water. One system called potable water not two systems called potable cold and potable hot.

If we think that the two pipes need bonding across a water heater then explain what would be the requirement should a short repair to the copper pipe be made with nonmetallic pipe? This is allowed by the plumbing code by the way.

Well let’s see what the Code Making Panel has to say about this repair.

5-235 Log #1834 NEC-P05 Final Action: Reject

(250.104(A)(1))

____________________________________________________________

Submitter: Mark T. Rochon, Mark J. Rochon Master Electrician

Recommendation: Revise as follows:

General Combination metal water piping system(s) separated by nonmetallic water piping system(s) where may become energized installed in or attached to a building or structure shall be bonded to the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where of sufficient size, or the one or more grounding electrodes used.

Substantiation: Nonmetallic water piping systems are being inserted between our metal water piping system and today’s code is not recognizing these changes.

Panel Meeting Action: Reject

Panel Statement: The conditions indicated in the substantiation are already covered by 250.104(B) where there is not a complete metallic water piping system.

Number Eligible to Vote: 15

Ballot Results: Affirmative: 15

Haint going to do it for anyone unless they can show an amendment adopted by their jurisdiction in writing making it a requirement.
 
I just noticed that the plumber used Teflon tape when he installed my hose bib on the outside of my home which has copper pipes. Do I need to bond this hose bib with a #2 copper conductor as I have a 300 amp service? Could someone tell me just how to accomplish this?
 
Let me get this straight. If you have an old water heater-mine is 5 years old and does not have dielectric fittings- then you require the bonding anyway. Is that correct?

Around here it has never been enforced to bond the hot water pipes. I think it makes good sense to bond across from the cold to the hot since those pipes do go into areas of the home where one could get hurt if they get energized. I don't see a need with the old water heaters but if in fact the new units are coming with dielectric fittings then it would seem appropriate to do so.
 
Dennis said:
Let me get this straight. If you have an old water heater-mine is 5 years old and does not have dielectric fittings- then you require the bonding anyway. Is that correct?Around here it has never been enforced to bond the hot water pipes. I think it makes good sense to bond across from the cold to the hot since those pipes do go into areas of the home where one could get hurt if they get energized. I don't see a need with the old water heaters but if in fact the new units are coming with dielectric fittings then it would seem appropriate to do so.
Who are you asking?
 
Dennis said:
Anybody, but your post seem to suggest that
Then I will answer to clarify my OP.

IF you had dielectric fittings on your water heater AND you lacked any metallic mixing valve such as for a shower, then I would require a bond at some point between the hot and cold. There have been times where the hot and cold pipes ran right next to each other in a location other than the water heater and I found that bonding to be acceptable.

I rarely see the lack of a mixing valve so this is usually never an issue.

What I do see a lot, however is when a water treatment company comes in and puts their system in near the water main and uses all non metallic pipes at which point we have a problem with the 200' of pipe on the other side of the main water bond but that's another story.
 
We required a jumper for a few years and then stopped.

Some of us took it a step further and extended the jumper to the gas pipe.

I for one see the jumper from cold, hot and gas, as a good idea.
 
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jar546 said:
Then I will answer to clarify my OP.IF you had dielectric fittings on your water heater AND you lacked any metallic mixing valve such as for a shower, then I would require a bond at some point between the hot and cold. There have been times where the hot and cold pipes ran right next to each other in a location other than the water heater and I found that bonding to be acceptable.

I rarely see the lack of a mixing valve so this is usually never an issue.

What I do see a lot, however is when a water treatment company comes in and puts their system in near the water main and uses all non metallic pipes at which point we have a problem with the 200' of pipe on the other side of the main water bond but that's another story.
Your big IF assumes that you are able to verify a mixing valve at each service upgrade inspection. I would find that difficult.

My first thought is that the electrician would rather install a jumper.
 
Why is there a dielectric fitting on the water heater?

The issue of plastic pipe being added causes many questions. When this was brought up at the meeting in Raleigh, NC, with many members of the code making panel there, I asked at what point does the plastic not require a jumper. I have seen inspectors make a contractor put a jumper to every copper pipe that was stubbed down into the crawl space when they remolded the house and added plastic thru the crawl area. To me this was just wrong.

The problem is the code as written would exempt any copper from being bonded if it were not a complete system of metal pipe. So if you add 2" of copper then theoretically no bond is needed as Mike would agree, I believe. So for those who don't agree with that then at what point does it get ridiculous to bond around every piece of plastic?
 
Dennis, I completely understand where you are coming from. Many systems are being broken up into sections of copper and plastic. Some things that I have done in the past:

1) Entire system is PEX but there is a large copper manifold about 36" long, fed by PEX from the water meter that distributes to the rest of the PEX installation. In this case, I saw no reason to add bonding to that manifold. The copper pipe coming in at the water service was sufficient for bonding.

2) Copper water service, then PEX for water conditioner then rest of house was copper. In this case I thought it was prudent to bond from the water main to the cooper system on the other side of the conditioner.

I believe that jwelectric's issue is that the bonds should go back to the panel, not from pipe to pipe. Am I correct JW?
 
250.104 Bonding of Piping Systems and Exposed Structural Steel.(A) Metal Water Piping. The metal water piping system shall be bonded as required in (A)(1), (A)(2), or (A)(3) of

this section. The bonding jumper(s) shall be installed in accordance with 250.64(A), (B), and (E). The points of

attachment of the bonding jumper(s) shall be accessible.

(1) General. Metal water piping system(s) installed in or attached to a building or structure shall be bonded to the

service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where of

sufficient size, or to the one or more grounding electrodes used. The bonding jumper(s) shall be sized in accordance

with Table 250.66 except as permitted in 250.104(A)(2) and (A)(3).
Note that the words jumper and system are also plural. Certainly this question has been addressed by a code making panel. What was the outcome of that?

We allowed the jumper to be located at the laundry as well as the water heater.

 
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jar546 said:
I am at a loss for words for what I am seeing here. Are you sure you are in California and not a 3rd world country?
SoCal has all types of areas just as does the rest of the country. I only show the outlandish examples. Shirley I can find similar examples anywhere in the USA. I just happen to encounter a lot of it.
 
jar546 said:
I believe that jwelectric's issue is that the bonds should go back to the panel, not from pipe to pipe. Am I correct JW?
250.104 is clear on where the bonding is to take place. It mentions four places that the bonding is to take place and for the life of me I can't find hot to cold anywhere.

250.104 Bonding of Piping Systems and Exposed Structural Steel. See related ROP

(A) Metal Water Piping. The metal water piping system shall be bonded as required in (A)(1), (A)(2), or (A)(3) of this section. The bonding jumper(s) shall be installed in accordance with 250.64(A), (B), and (E). The points of attachment of the bonding jumper(s) shall be accessible.

(1) General. Metal water piping system(s) installed in or attached to a building or structure shall be bonded to

1- the service equipment enclosure,

2- the grounded conductor at the service,

3- the grounding electrode conductor where of sufficient size,

4- or to the one or more grounding electrodes used.

The bonding jumper(s) shall be sized in accordance with Table 250.66 except as permitted in 250.104(A)(2) and (A)(3).

Anything less than this requirement is nothing more than a wish of someone who thinks something is good instead of something required.

The code making panel in their statement says anything that is not a "complete" metal piping system is to be bonded by 250.104(B) so should someone somehow think that it needs a jumper from one pipe to the other pipe is wrong.

The bonding of gas piping has never been allowed to hit a water pipe unless is was the part of the pipe that is underground or the first five feet inside leading to the underground portion of the system.

We can't enforce a picture we saw somewhere or something someone thinks is a good idea. We can only enforce what is written.
 
So does that mean that you have to run separate conductors to two ground rods? When a jumper is installed across a water meter for example, does that mean that they should have run 2 wires back to the first disco for the service?

The bond between the hot and cold simply ensures that the metal waterpipe system is bonded to 1-4
 
jar546 said:
So does that mean that you have to run separate conductors to two ground rods? When a jumper is installed across a water meter for example, does that mean that they should have run 2 wires back to the first disco for the service?The bond between the hot and cold simply ensures that the metal waterpipe system is bonded to 1-4
The requirement for bonding of grounding electrodes is found in Part III of Article 250 but the bonding of a metal piping system is found in Part V of Article 250.These are two very different types of bonding.

When we bond across a water meter that is within the first five feet of the metal pipe as it enters a building we are doing a Part III electrode bond and a Part V interior metal pipe bond.

Yes it would be permissible to run the 250.52(A)(1) and the 250.104(A)(1) with separate conductors just as it would be permissible to run a separate conductor to all 8 of the electrodes described in 250.52.

The requirement that cannot be found in the NEC is to install a bonding jumper between the hot and cold potable water pipes.

In the 1975 code cycle in 250-50 there was a requirement that any and all metal piping systems installed were to be made electrically continuous but this requirement was removed by the 1981 edition. The old habit of doing this is still around today.

Also in the ’75 edition a two prong receptacle could be replaced with a three prong receptacle and the EGC carried to the closest cold water pipe. The use of the hot water pipe was not allowed even though there was a requirement to make the piping system electrically continuous.

By the ’81 edition the code making panel realized that they had no control over the plumbing rules and this was abolished and the requirement was to land the EGC to the service at either the neutral or grounding electrode.

In today’s code there is no requirement to make and keep a metal water pipe electrically continuous. Even if there was a bond done at a water heater what is to stop a plumber from repairing the metal pipe with a nonmetallic repair just above the bonding? If this is done just what is the benefit of the bond?
 
As defined by the ICC what is a water heater?

WATER HEATER. Any heating appliance or equipment that heats potable water and supplies such water to the potable hot water distribution system.

Well then what is potable water?

POTABLE WATER. Water free from impurities present in amounts sufficient to cause disease or harmful physiological effects and conforming to the bacteriological and chemical quality requirements of the Public Health Service Drinking Water Standards or the regulations of the public health authority having jurisdiction.

So by the definition of potable water and water heater by the plumbing codes is there two different systems that need to be bonded by the NEC?

NO!

Then why all this uproar about bonding across a water heater?

Maybe it is because of the lack of knowledge of just what is required by the NEC and the (s) found at the end of word “system”

Just how many different water systems are there in a building?

At least two.

GRAY WATER. Waste discharged from lavatories, bathtubs, showers, clothes washers and laundry trays.

POTABLE WATER. Water free from impurities present in amounts sufficient to cause disease or harmful physiological effects and conforming to the bacteriological and chemical quality requirements of the Public Health Service Drinking Water Standards or the regulations of the public health authority having jurisdiction.

Can either or both be in metal pipes?

Yes!

Does this explain the (s)? It does to some of us like those on the CMP in the proposal I posted.

The requirement to bond a metal water pipe is the end of the conductor that lands on the pipe is to be accessible and the other end is to land at one of four places outlined in 250.104(A)(1).

Why do any bonding in the first place? Is it to establish an Effective Ground-Fault Current Path or a Ground-Fault Current Path? Is there a difference between the two?

Effective Ground-Fault Current Path. An intentionally constructed, low-impedance electrically conductive path designed and intended to carry current under ground-fault conditions from the point of a ground fault on a wiring system to the electrical supply source and that facilitates the operation of the overcurrent protective device or ground-fault detectors on high-impedance grounded systems.

Ground-Fault Current Path. An electrically conductive path from the point of a ground fault on a wiring system through normally non–current-carrying conductors, equipment, or the earth to the electrical supply source.

If it is for either of these two then it is clear that the bonding is to be carried to the electrical supply source not from one pipe to another pipe.

Comments.
 
It is about the break of continuity in the metallic piping system to ensure it is bonded. Real simple. It does not matter if it is a water heater, a boiler, water conditioning system or whatever. If it breaks the continuity of the metallic piping system then a bond is needed. Good luck with your CMP submission, I hope you get what you want. Until then, on the 1 out of every 99 jobs that does not have a metallic shower mixing valve and a water heater that breaks the continuity by its design, we every electrician in our jurisdiction will be bonding the break in the line, no matter where it is. Many actually do it whether it needs it or not.
 
In 300.10 electrical continuity is a requirement

In 300.12 mechanical continuity is a requirement

In 314.3 requires electrical continuity

In 250.53(D)(1) continuity to the electrode of the first five feet is required

What I can’t find anywhere in the NEC is a requirement to make the plumbing pipes electrically continuous or to make a gas pipe electrically continuous. Could you point out this requirement for me please?

The NEC addresses the installation of electrical equipment including raceways and cables. I can’t find anywhere in the NEC that requires any type of installation requirements for plumbing or gas pipes.

I do see the requirement to bond these items if they are a complete system but a complete system will have continuity all by itself without any bonding around anything. Where is the requirement to bond around any nonmetallic parts of a plumbing system? 250.53(D)(1) says we can bond the 250.104(A) to the 250.52(A)(1) if we so desire but there is not a requirement that the bond has to be here.

Help me to understand why someone would install a bonding jumper at a water heater.
 
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