Bonding both hot and hold supply pipes

[Kenton H. Shepard, CMI]

I almost never see the hot and cold pipes bonded together at the water heater. I often see one or the other but it seems to me there ought to be a jumper between the two. Is this an AHJ issue?

[jtedesco1]

Originally Posted by kshepard

I almost never see the hot and cold pipes bonded together at the water heater. I often see one or the other but it seems to me there ought to be a jumper between the two. Is this an AHJ issue?

No it is a requirement:

See 250.104(B) Other Metal Piping

[Kenton H. Shepard, CMI]

Well I virtually never see a jumper to the hot water piping and almost never see the hot pipe bonded. Do you see it bonded correctly at the hot water heater most of the time? Anybody? Anywhere?

[Brian E. Kelly]

Predominantly bonded @ the water heater correctly.

[Shawn Rowe]

Originally Posted by jtedesco1

No it is a requirement:
See 250.104(B) Other Metal Piping

JOE,
was this just added/changed for the 2005 NEC?


KENTON,
I would say that 80+% of the homes (with metal pipes) I inspect do NOT have jumpers!

[Barry Adair]

This was bonding from cold water supply clamp for WH flues, chimneys, gas piping, and the jumper for H/C water supplies at the twin WHs at a new build in Frisco, TX this year. This is the only one I've seen done this way so far. The WHs did have dielectric unions.

[Kenton H. Shepard, CMI]

I just finished discussing this with inspectors at the local building department who told me that it's a matter of interpretation. They require the cold water pipes to be bonded, preferably to the grounding bus bar in the main panel or to a grounding electrode rather than the water pipes because plastic main water lines are sometimes used underground here. They recommend bonding the hot water pipes but they don't call it a defect if they don't see it.

[Michael Larson]

Originally Posted by badair

This was bonding from cold water supply clamp for WH flues, chimneys, gas piping, and the jumper for H/C water supplies at the twin WHs at a new build in Frisco, TX this year. This is the only one I've seen done this way so far. The WHs did have dielectric unions.

Barry,
Are the water pipes bonded as well?
I can't tell from your picture. I only see the flues bonded to ground.
Is there any chance this is for lightning?
I have never seen this has anyone else?

[Barry Adair]

Hypothetical questions about previous post.

With this flue bonding set up could the roof exposed flues become "lightning rods" and electrocute someone showering, let's say standing in a metal tub, touching the plumbing control knobs?

Or would the strike always go back to ground?

[Kenton H. Shepard, CMI]

Lightning strike or home current getting onto the pipes accidently. That was my concern.

[Barry Adair]

Michael,
As posted this WAS BONDED clamped at cold supply entry to this house.
I can't locate the H-C jumpers photos right now but I am seeing H-C jumpers more often on new builds. Not all but they are out there.

Others,
Please reply to post #9

[Jeffrey R. Pope]

The bonding of those vents does nothing and is not required. The draft hoods do not make a good enough connection to even bond the tanks.

I see no hazard with this setup, but I see no benefit either.

[Peter Doane]

Here is a good read for Grounding -v- Bonding (Sorry its not one link, it was a series of articles last year)

http://www.ecmweb.com/mag/electric_g...ing/index.html
http://www.ecmweb.com/mag/electric_g...g_2/index.html
http://www.ecmweb.com/mag/electric_g...g_3/index.html
http://www.ecmweb.com/mag/electric_g...g_4/index.html
http://www.ecmweb.com/mag/electric_g...g_5/index.html
http://www.ecmweb.com/mag/electric_g...g_6/index.html
http://www.ecmweb.com/mag/electric_g...g_7/index.html
http://www.ecmweb.com/mag/electric_g...g_8/index.html
http://www.ecmweb.com/mag/electric_g...g_9/index.html
http://www.ecmweb.com/mag/electric_g..._10/index.html
http://www.ecmweb.com/mag/electric_g..._11/index.html
http://www.ecmweb.com/mag/electric_g..._12/index.html

[jtedesco1]

Originally Posted by srowe

JOE,
was this just added/changed for the 2005 NEC?


KENTON,
I would say that 80+% of the homes (with metal pipes) I inspect do NOT have jumpers!

Checking earlier editions will show the same words around the Section 250-80 area, and the following has been in the NEC for many years:

FPN: Bonding all piping and metal air ducts within the premises will provide additional safety.

[Kenton H. Shepard, CMI]

I spent about 20 minutes talking with the county building inspectors, they were pretty relaxed and they'd been discussing it between themselves for a few minutes before they finally called me in.

I told them I was concerned about safety and liability and they just kind of rolled their eyes and in the ensuing discussion it was plain that so were they but that grounding and bonding (they made it plain) were one of the most difficult issues to nail down, Things keep changing and are different in different jurisdictions.

Around here, I think the main issue is that you're recommendations must be written to keep people safe and your knowledge must be on a par with local practices generally accepted by local building officials.