Copper supply pipe bonding questions

**mark petty** · 08-15-2019, 06:09 AM

Central Florida: Typically I see the bond wire for the copper water supply piping attached to piping just above the water heater. Sometimes I can't find where it is bonded but when checked; I find that it is bonded. Question # 1: Where else (out of sight) would it be bonded. Question # 2: Did a home the other day where the bond wire above the water heater was totally disconnected from the supply piping; I did a bond check anyway and found that the piping, was in fact, still bonded. What gives? Thanks, Mark

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**Jim Robinson** · 08-15-2019, 06:22 AM

My other spot that I find is at the shut off valve where the water is coming into the house. After that it's a note in the report that I could not verify the location. A lot of times they bury it in the wall too far and it gets covered by the sheet rock installer.

**Jerry Peck** · 08-15-2019, 06:35 AM

Originally Posted by mark petty

Question # 1: Where else (out of sight) would it be bonded.

The bond connection is required to be accessible, thus it would need to be visible.

Question # 2: Did a home the other day where the bond wire above the water heater was totally disconnected from the supply piping; I did a bond check anyway and found that the piping, was in fact, still bonded. What gives?

If the bond wire was off, it was no longer bonded - bonding is intentionally creating a specific minimum electrically conductive path ... which was disconnected.

What you found when you checked for continuity was that there is an unintentional electrically conductive connection somewhere - that unknown connection may not even be a permanent (an intentional good, tight, electrically conductive) connection.

I would report that as the bonding connection was disconnected, I would NOT in anyway, state or imply in your report that you 'checked bonding by checking continuity and found that it was bonded'.

**mark petty** · 08-15-2019, 09:49 AM

Originally Posted by Jerry Peck

The bond connection is required to be accessible, thus it would need to be visible.

If the bond wire was off, it was no longer bonded - bonding is intentionally creating a specific minimum electrically conductive path ... which was disconnected.

What you found when you checked for continuity was that there is an unintentional electrically conductive connection somewhere - that unknown connection may not even be a permanent (an intentional good, tight, electrically conductive) connection.

I would report that as the bonding connection was disconnected, I would NOT in anyway, state or imply in your report that you 'checked bonding by checking continuity and found that it was bonded'.

Jim, Jerry I did just as you said; thank you both for your help.

**Charles Buell** · 08-21-2019, 04:20 AM

Around here, the hot and cold water pipes are considered bonded when there is a tub/shower mixing valve installed.

**Bryce Nesbitt** · 08-21-2019, 08:36 AM

Just watch out if there is a dielectric fitting. That's an electrically isolating fitting used to prevent dissimilar metals from corroding each other.

In that case each side is considered electrically isolated, and if required, must be separately grounded.

**Charles Buell** · 08-21-2019, 08:38 AM

Originally Posted by Bryce Nesbitt

Just watch out if there is a dielectric fitting. That's an electrically isolating fitting used to prevent dissimilar metals from corroding each other.

In that case each side is considered electrically isolated, and if required, must be separately grounded.

Bonded

**mark petty** · 08-21-2019, 10:31 AM

Originally Posted by Charles Buell

Bonded

Charles, Bryce
All good points, thanks

**Jerry Peck** · 08-21-2019, 12:47 PM

Being as we are parsing words ...

Originally Posted by Charles Buell

Around here, the hot and cold water pipes are considered bonded when there is a tub/shower mixing valve installed.

I suspect that the wording should be changed from: "hot and cold water pipes are considered bonded when there is a tub/shower mixing valve installed" to (see all cap text I inserted) "hot and cold water pipes are considered bonded TO EACH OTHER when there is a tub/shower mixing valve installed" ... however, that does not "bond" (to ground) the hot and cold water pipes.

Additionally, if the piping is not metallic (which was also not stated), then a shower mixing valve would not matter ... or if the piping system was copper and the valve has been replaced using CPVC into the valve and from adapters ... which is not something one would know ... thus the bond between the cold and hot water piping at the water heater is still the way to go.

**Charles Buell** · 08-21-2019, 01:42 PM

If the piping is plastic there is no bonding requirement for the water heater itself. Of course assuming the cold side of metal piping is bonded somewhere the hot is then considered bonded through a shower valve. Redundancy by putting a jumper at the water heater is fine too.

**Jerry Peck** · 08-21-2019, 03:00 PM

Originally Posted by Charles Buell

If the piping is plastic there is no bonding requirement for the water heater itself. Of course assuming the cold side of metal piping is bonded somewhere the hot is then considered bonded through a shower valve. Redundancy by putting a jumper at the water heater is fine too.

The issue of bonding the hot to the cold at the water heater is to avoid breaking the bond when work is done on the copper piping system and repairs or alterations are made, even the use of SharkBite fittings breaks the bond path, using adapters and CPVC is no different, or, should I say, using SharkBite fittings is no different than using CPVC as both break the bond.

You are correct in one thing: if the piping is plastic, no bonding is required ... no matter how many times an inspector tells a plumber to 'bond that pipe', however, when one sees a bond wire hanging loose by a water heater and sees CPVC piping at the water heater ... that bond wire handing loose is telling you 'Hey, look at me! Can you guess why I was here?" ... and hopefully one understands what that bond wire is telling one.

**Rollie Meyers** · 08-31-2019, 07:28 PM

Sharkbite fittings seem to isolate metallic pipe, got curious one time at a scrap yard with some copper pipe with a Sharkbite coupling, & brought out a multimeter to check, I had no continuity between the pipe on either side of the coupling.

**Jerry Peck** · 09-01-2019, 06:11 AM

Originally Posted by Rollie Meyers

Sharkbite fittings seem to isolate metallic pipe, got curious one time at a scrap yard with some copper pipe with a Sharkbite coupling, & brought out a multimeter to check, I had no continuity between the pipe on either side of the coupling.

Correct. Even SharkBite began acknowledging that SharkBite fittings in metallic piping systems need to have a bonding jumper across them.

**Joe Reilly** · 09-04-2019, 01:46 PM

Most of the time in California, I find it on the gas line near the meter. Occasionally it is above the water heater. I have been known to see it on the plumbing under the kitchen sink though, depending on how old the house is.

- - - Updated - - -

Most of the time in California, I find it on the gas line near the meter. Occasionally it is above the water heater. I have been known to see it on the plumbing under the kitchen sink though, depending on how old the house is.

- - - Updated - - -

Most of the time in California, I find it on the gas line near the meter. Occasionally it is above the water heater. I have been known to see it on the plumbing under the kitchen sink though, depending on how old the house is.