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'shocking' problem and replace water heater element

Posted by peonyfan (My Page) on
Thu, Sep 1, 11 at 21:37

I mentioned a problem we are having getting shocked at the sink and shower (when using water) to an HVAC contractor who was giving me a bid on something else. This problem has stumped two electricians. We can't predict when the shocks happen, and they don't happen when the electricians come. The HVAC guy offered to check my water heater (he also installs water heaters) to see if. . .I apologize, but I can't remember what he was checking. . .maybe if something was burned out. . .it was fine though. He did suggest that we replace our water heater element (and said that if we are handy we could easily/cheaply do it ourselves) because doing this might possibly solve the problem with the possibility that part of our system is not bonded. We are probably going to get a new water heater within the next year, after we finish some higher priority projects, so I wonder before my husband or I spend the time on learning how to do this, does anyone have an understanding of how changing the element might help the problem with the shocks. This is an older house (1960s) and wiring problems have turned up in renovating other parts of the house. Thank you!


Follow-Up Postings:

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RE: 'shocking' problem and replace water heater element

An electric water heater element is basically an electrical resistance heating element inside a metal tube.

Generally when the water heater elements fail they either burn out or become some crusted with mineral scale that they can no longer heat, but occassionally we find one where the metal tube has split longitudinally and exposes the electrified heating element directly to the water. In most instances when that occurs the thermostat will trip out on overload, but sometimes, although very rare, it does not trip out, but it electifies the water and piping so you get that shock.

If you are getting a shock it is an extemely dangerous situation that must be corrected immediately for your own safety.

YOur HVAC man/woman is correct. Changing the elements is a rather simple DIY job and you can buy replacement elements at any hardware or home supply for about $13 each.


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RE: 'shocking' problem and replace water heater element

"If you are getting a shock it is an extemely dangerous situation that must be corrected immediately for your own safety."

Please pay attention to this sentence.


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RE: 'shocking' problem and replace water heater element

The problem with a cracked electric heating element is that the breaker feeding the heater is probably at least 30 amps.

Water is NOT a good enough conductor to allow that much current to flow at 120 V, so it will not trip a breaker.

It takes a LOT less than 30 amps to kill you, and you have enough salt in your body that you are much better conductor than the water.


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RE: 'shocking' problem and replace water heater element

I would also check to see if the electrical system is grounded to the plumbing system improperly. I have seen this several times. This can cause problems you mention. I suggest to have an electrician check the home for proper grounding and/or an interrupted ground ASAP. Evidence of improper grounds can be seen by electrolysis in the plumbing system and fixtures. This is indeed a VERY serious situation. I have a friend who was electrocuted in the shower because of a direct ground on the water line to his shower, done by a contractor after remodeling bathroom!
RJ


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RE: 'shocking' problem and replace water heater element

"I would also check to see if the electrical system is grounded to the plumbing system improperly."

Even with correct grounding a cracked element can energize the water enough to be dangerous without tripping the breaker.

The pipes can ALL be bonded to ground correctly, but the water is still a conductor.
Electricity takes EVERY PATH all the time.


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RE: 'shocking' problem and replace water heater element

I have had the very same thing before. It was a bad lower element. Dont play around, get it fixed soon!!


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RE: 'shocking' problem and replace water heater element

Thank you for all the replies. As long as we are not using this sink/shower, I assume it is not a safety issue, or? We have tape over the sink basin right now.


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RE: 'shocking' problem and replace water heater element

SIR OR MADAME....IT IS A CONSTANT/PERPETUAL/SIGNIFICANT/IMPORTANT SAFETY ISSUE!!!!!!!!!!

STOP EVERYTHING YOU'RE DOING OTHERWISE AND FIX IT!!!!!!!!!!!

Please.


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RE: 'shocking' problem and replace water heater element

Second Asolo:

There are two issues here:

1. how the sink has become electrified in the first place
2. why the plumbing isn't bonded to the electrical neutral and ground.

If the metal piping is correctly bonded and grounded, even if there is an electrical fault, it should never present a hazard to you.

The fact that you are getting shocked indicates that there are multiple failures. You need to get it fixed.

Presumably all of the plumbing is connected together - an electrical charge at one faucet means that all of the plumbing is potentially "hot".


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RE: 'shocking' problem and replace water heater element

Peonyfan,

Would you by chance have a portion of your water distribution piping as plastic, either PE, PVC, PEX or other plastic piping. If someone has run a ground to metallic piping on one side of the metallic piping and there is a plastic section inbetween the metallic piping and meter side this could be the cause. Electricity takes the path of least resistance and by running the water, could be grounding thru the water and into the drainage system. Replacing the plastic piping section with metallic piping would direct the ground through the piping. Otherwise I would try to track down the "Ground" connection which could be causing the shock. Have you had recent electrical work done? Check that first. Running a ground wire between the metallic piping sections would also direct the current into the piping.

Another thing to check, do you have a "Whole house filter" These are typically plastic and would break the ground. Run a ground wire from one side of the filter (Metal pipe) to the other side (Metal pipe).

Hope this helps you track the problem area.

Dan


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RE: 'shocking' problem and replace water heater element

"2. why the plumbing isn't bonded to the electrical neutral and ground.

If the metal piping is correctly bonded and grounded, even if there is an electrical fault, it should never present a hazard to you. "

Water is not a good enough conductor to trip the breaker, and you can do anything you want to the pipes, the water itself can still carry current (though the relatively high resistance limits how much can flow).

If you stuck a bare wire into a completely grounded metal can full of water, then touched the water you can receive a shock.


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RE: 'shocking' problem and replace water heater element

Yo, brickeyee and dan martyn....with respect, which I have for both of you...this person obviously has little idea what they're dealing with. Has little idea whether nuisance or critical. Nor do I. Nor do you. Cyber-distance doesn't cut it, here.

Time to hire somebody....NOW.....imho.


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RE: 'shocking' problem and replace water heater element

Never said otherwise.

If the sink is conducive and correctly bonded and you touch it and the water stream with a cracked heating element you can be shocked.

Usually it is touching a valve with the other hand testing the water.

As long as you are pretty dry it is hard to get a dangerous shock, but if you just got out of the shower your skin resistance is much lower and you could be hurt.

It ONLY takes a cracked heating element to do this.

Nothing else.


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RE: 'shocking' problem and replace water heater element

Good on ya! Smart fellow, too.


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RE: 'shocking' problem and replace water heater element

"Another thing to check, do you have a "Whole house filter" These are typically plastic and would break the ground. Run a ground wire from one side of the filter (Metal pipe) to the other side (Metal pipe)"

Water softeners will also break the ground as many bypass valves are non-conductive material.


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RE: 'shocking' problem and replace water heater element

If the ground was broken they would be less likely to receive a shock form a cracked heating element.


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RE: 'shocking' problem and replace water heater element

I agree that it calls for a qualified professional - possibly two.

The requirement to bond the metal plumbing to the electrical neutral (which is also bonded to a ground electrode(s))is a NEC requirement as is the requirement to bond metal pipes between all non-conductive piping (water heater, water softener, dielectric unions, PRV's, plastic pipe sections,water meters, etc.) In some areas, the metal gas line must be bonded also.

Isolated metal sections (such as a metal faucet in an otherwise non-metal plumbing system) typically don't have to be bonded.

Because of the popularity of plastic plumbing, the domestic water piping system is no longer accepted as the only grounding electrode for residential electrical service. In other words, a properly bonded plumbing system that has at least 10' of metal pipe in the ground may be used as a grounding electrode, but it may not be the exclusive grounding electrode - you need a ground rod or other ground in addition to it. Metal gas lines may never be used as a grounding electrode but may be required to be electrically bonded in some jurisdictions.

Electrical bonding across non-conductive plumbing fittings is typically done with ground clamps and #4 bare copper wire - but check code for the proper conductor size.

If any part of the plumbing system becomes energized, the current is carried back to the neutral bus via metal bonding conductors, not via an earth ground. That's a critical point: Earth is really a poor conductor and isn't an acceptable path back to the neutral bus.

I agree that in a situation where all of the plumbing is plastic, you could get shocked from energized water (say from an electric heater element). A properly grounded water heater would minimize that likelihood, but it's possible.

I disagree that a properly bonded metal plumbing system would conduct electrical current through the water without bleeding that current back to the neutral first.

If I were this homeowner, I would want two things:

1. The source of the electrical fault fixed.

2. A complete inspection and repair of the electrical bonding of the plumbing system, electrical service and grounding equipment (which could be the source of the electrical fault in the plumbing - think of a bonded but ungrounded plumbing system with an open neutral feeder to the breaker panel).

Unless this is an all-plastic plumbing system, both things have failed.


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RE: 'shocking' problem and replace water heater element

*****UPDATE/RESOLUTION******

Thanks for the replies. I had a team of two electricians come in today. It took them 2.5 hours to find the culprit--our foyer light fixture, which is a few steps away from the bathroom in question. Also there is a plastic pipe, and as I understand it, had this pipe been metal, it would have caused the breaker to short out, but since it was plastic, we got a shock. Of course this had to be the light fixture that I liked and not the one I was planning on replacing for aesthetic reasons. ;) There was a fabric (?)-coated wire that was wearing away and touching metal. Since we were experiencing the shocks only intermittently, vibrations from opening and closing doors might explain it. The water heater seems to have been a red herring. I need to follow up with the electricians about what happens when we have a faulty fixture or the like again, what do we need to have done (if anything) to make it trip the breaker instead of shocking us.


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RE: 'shocking' problem and replace water heater element

If the post is truly what they spoke, I am further confused. But if the shock originated at the light fixture, at least part of your equipment grounding system is faulty. Or maybe you were fed some baloney.


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RE: 'shocking' problem and replace water heater element

"I disagree that a properly bonded metal plumbing system would conduct electrical current through the water without bleeding that current back to the neutral first."

there is not "first."

Current will flow in every path available and the amount is determined by the impedance of the path.

It is NOT an All the current takes this path thing.

While some will indeed return through bonded conductive pipes, some will still return though the water itself and any lower impedance path created (like a human body to a well bonded faucet).

All the current will be returning through the pipe until YOU put yourself in the path.

Then some diverts through you.


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RE: 'shocking' problem and replace water heater element

And your power bill will increase, perhaps dramatically.


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RE: 'shocking' problem and replace water heater element

"Then some diverts through you."

"And your power bill will increase, perhaps dramatically."

Be the first to pay your bill posthumously.


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