water heater

[JoeNorm]

I am unclear on the grounding requirements for a tank hot water heater in a residence(new construction).

The house is all PEX besides the flex lines and pressure relief line which is piped in copper off the tank. Do I need to bond any of this piping? What type of ground wire do you typically run after the Romex junction in the wall(assuming that is how it was wired)?

 

[LarryFine]

Only the supply GEC is required.

 

[mopowr steve]

Only the supply GEC is required.

Think you meant Equipment Grounding Conductor
And no further bonding is necessary to the short piece of copper for pressure relief or metal flex lines.

 

[Dennis Alwon]

You don't need to bond and of those fittings. Just run the nm cable to the unit and ground it with the equipment grounding conductor.

 

[kwired]

The water heater itself needs an equipment grounding conductor sized per branch circuit OCPD 250.122 in all cases.

If you have a metallic piping system it needs bonded per 250.104, it possibly needs bonding jumpers around the WH inlet/outlet. This bond has nothing to do with the EGC of the supply circuit, it is for bonding the piping system, and in most cases will be a larger conductor than the EGC to the WH is.

Short lengths of pipe like for the relief valve are not a "piping system" and needs no separate bonding for it. Neither does a short length of metallic piping in an otherwise non metallic piping system.

 

[infinity]

You don't need to bond and of those fittings. Just run the nm cable to the unit and ground it with the equipment grounding conductor.

Agreed. Nothing required beyond that.


Dennis,
I see that your signature goes with you avatar.

 

[LarryFine]

Think you meant Equipment Grounding Conductor

I did. I absolutely did mean the EGC.

 

[Dennis Alwon]

Agreed. Nothing required beyond that.


Dennis,
I see that your signature goes with you avatar.

Yeah... that is how Jim Morrison came up with "The Doors" as a band name.

 

[Eddie702]

What if it is a gas water heater with no electrical feed?

 

[texie]

What if it is a gas water heater with no electrical feed?

Then, in this scenario, it needs nothing.

 

[LarryFine]

What if it is a gas water heater with no electrical feed?

Then there is no electrical source "likely to energize" the water heater.

 

[Eddie702]

Then there is no electrical source "likely to energize" the water heater.

True. I suppose with pex no bondingis required but what if it was partial pex/partial copper?

 

[ActionDave]

True. I suppose with pex no bondingis required but what if it was partial pex/partial copper?

If it is predominantly pex with some bits of copper here and there, like those stub outs they use at the fixtures then you don't have a metallic piping system and no bonding is required.

 

[kwired]

What if it is a gas water heater with no electrical feed?

If metallic water piping you possibly need bonding jumper between hot and cold water lines. As NEC is written it could be anywhere in the system, even a metallic fixture body (shower valve is common place) that has both lines connected to it can provide that bonding. Some local jurisdictions have their own amendments and want that bond at a place where it can be easily observed (more like easily found by their inspectors) often at or very near the WH.

 

[oldsparky52]

One day I guess someone will figure out that we need to have a water bond in the house the way we do at the pool.