Electric shock hazard with electric hot water heaters

Originally Posted By: ieisenstein
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Here is a WATCH OUT FOR regarding electrically powered hot water heaters:



I did an inspection on a beach house, with an electric water heater.
The serial number on the water heater indicated October 1985, yet the water heater looked nearly new, so I decided to look it up and get a confirmation of the age (If it's 20 years old, you want to say "past its useful life", but if it's really newer, you don't want to say that).

So in looking up the model number, I stumble onto someone's posting of a problem with that particular model... The guy says in the posting that his wife had gotten an electric shock when connecting a hose to the hose outlet. He got an electrician who traced it back to the hot water heater. The anode inside the heater (same heater I had in this house) had corroded and was putting electric charge into the water, and 100 volts was measured at the faucets in the house to "ground".

Now this would ordinarily make no sense because plumbing is supposed to be grounded, so how could you get an electric shock from it, but if you have a water well (instead of city water), very often the pipe coming from the well is plastic, so the plumbing might actually NOT be grounded. That was the case in the house where the guy had the electric shock problem.

The beach house I inspected has city water, but there was a rubber hose section that bridged between the service pipe sticking out of the garage floor, and the house plumbing. The house had a flat rate water bill so there was no water meter either.

So in my H-I report to the buyer, I made a precautionary recommendation that the electric circuit breakers that power this hot water heater should be changed for GFCI protected circuit breakers which would protect against that problem.

This time I noticed the section of rubber hose, but I might miss it next time, so I will put that recommendation in as a standard rec any time I see an electrically powered hot water heater.

BTW... The water heater was 20 years old, but is not past it's useful life because the house is shut down over the fall and winter every year, and the water heater is drained for 9 months of each year, so in reality, this HW heater only has 5 years of use on it.

Ira Eisenstein
Strictly Business Home Inspections
908-202-2208 / 732-438-6564
strictly-business@earthlink.net
www.strictlybusinesshomeinspections.com


Originally Posted By: rcooke
This post was automatically imported from our archived forum.



It would not be the anode . It does not carry any power it would be the element that had burned out and gone to ground.


This can also be a big problem if it happens the element can now be on 120 volts to ground . This could possible to have it on all the time and the thermostat might not shut it off. This is why TPR valves are so important.


there have been some that have exploded and destroyed the home . One Tank went over 400 feet . The water just gets hotter and hotter you can under house pressure have water at 240 degrees till the tank lets go then it immediately flashes to steam . The tank can become a rocket ship as water to steam I believe expands 1200 times .


I have it some where in My ark archives will try and find it tomorrow after I get home from Inspections .



Roy Cooke Sr.


http://Royshomeinspection.com

Originally Posted By: Greg Fretwell
This post was automatically imported from our archived forum.



The ground wire is probably not connected solidly.


Thje outer skin of the element is metal and securely bonded to the tank, but if the tank is not grounded that voltage could get to the water.


Originally Posted By: rcooke
This post was automatically imported from our archived forum.



2005 6:57 AM Post subject:




Greg Fretwell wrote:
The ground wire is probably not connected solidly.
Thje outer skin of the element is metal and securely bonded to the tank, but if the tank is not grounded that voltage could get to the water.


Thanks Greg I should have said that too . I was tired .

This not the one I wanted but it shows how important TPR valves are .

http://www.electrical-contractor.net/The_Store/Cr/RPlumb_Insp_Back.htm


--
Roy Cooke Sr.

http://Royshomeinspection.com