# Another GFCI Problem



## WestCoastPlumber (Jun 17, 2008)

I was getting F76 code from a pair of Noritz, so I replace dthe communication cable, had a problem with the GFCI, told the customer he needed to get this repaired, so a couple weeks later, no power to units at all, no power to remote, I told him how to go and reset the GFCI, he did, and power to both units.

I know that GFCI's are popular among electricians, I have seen sump pumps on them and tankless, but why? I have an electrician that I refer all the replacements too.

I know I was told that having a gfci will protect the circuit board, is this the only reason for it? Is it worth the constant problems? Can the tankless be wired with their own circuit breaker? Sounds better to me, maybe not as sensative though.

Feed back is good and appreciated


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## nhmaster3015 (Aug 5, 2008)

GFCI's detect leakage to ground, not neutral. If it is continuously tripping then either the gfci is bad (happens but not too often) or there is a problem on the load side. I can see no way that a gfci would protect the circuit panel.


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## pipes (Jun 24, 2008)

Not exactly NH, GFCI's do not depend on the ground at all. They measure the difference in voltage between hot and neutral. As far as protecting the panel, I doubt it , a GFI is not a surge protector. 
I ask my electrician not to install a GFI unless required by his code, I hate the nuisance calls.


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## rocksteady (Oct 8, 2008)

robert, i'm sure you know that gfci outlets need to be installed in wet locations. this is for safetly issues since those locations (bath, kitchen, etc.) are where people are and they could get shocked. that would be why a sump pump or an exterior tankless would need them. one of the problems with them is that if there is anything on the circuit (not just what's plugged into the gfci) that has a problem, it'll pop the interupter. sometimes that can be a little tough to track down.



paul


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## Airgap (Dec 18, 2008)

A designated circuit for the heater should help. That will be difficult in some cases though.


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## Tankless (Jun 12, 2008)

I see ec 760 all the time on tankless heaters. Usually means that when the units are powered on and someone unplugs the remote it can flash up that error. 760 will not cause improper ignition or heating. It's just letting you know to make sure the comm cable is intact.
Issues with GFI's and tankless just don't exist....I know you don't want to hear it but it is fact. I do see my fair share of Lutron & Levitron GFI's that fail. I only install Cooper GFI's. Pass and Syemore are good too.

The job of the GFI is to measure the difference between the hot and neutral. There does not need to be a ground wire present for the GFI to function, infact that is part of a code requirement when upgrading receptecals. But that is another story.

Todays GFI's are much more exacting that those of 5 - 10 years ago. The false tripping has gone way down. Imagine a big motor just starting to spool up, THAT is a difference maker between hot and neutral. Arcing at another recept down the line can cause a ground fault. Neutral is also known as the grounded conductor. When electricity leaks from the hot to the neutral, that neutral is grounded at the main panel. This is what the GFI is looking for. Surge suppresion is not the job of OTC GFCI's. GFI's can and no doubt do offer another layer of protection. This is fact,not my opinion. I have seen boards fry from surges with the GFI perfectly in tact. I have seen GFI's totally burnt up and no longer wsorking while the tankless electronics were left totally in tact.

I posted about a month or two ago on a customer that had power issues one windy evening. Her tankless stopped and long story short her GFI tripped. It was prolly when power got restored everything on that circuit was loading back up and caused an indifference, so the GFI tripped as it should. Customer reset it and all is well. 

Robert if the issue continues, the circuit that your sparky tagged needs to be looked at a little more closly...and / or tell your guy to install a Cooper GFI. I seriously have well over 250 tankless heaters ALL on GFI...indoors or out, no issues what so ever. 
Tell your client to hang tight, as time will help determine if there is a problem. Don't loose faith in GFI's, should they be needed just once it is worth all the trouble and effort one may have to put in.


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## WestCoastPlumber (Jun 17, 2008)

Thanks Tankless.

I understand GFI's have to be installed in wet locations, this is fine, but that is if the unit is plugged into the GFI's, why not just put in a switch and a junction box? no plug, and don't wire the tankless through the GFI, so when the GFI pops, then the tankless goes off also.

I understand Tanklesses stand, and I highly respect his thoughts. I just like my pumps and tankless to be hardwired into a junction box, with their own switch, and as an added bonus, have a dedicated circuit, but I know this is usually to much to ask for.  If the breaker pops, there is for sure a problem.

On with the GFI's, I will leave it up to the Sparkys to make their decisions based on code. :thumbup: :thumbup: Tankless, what is the code? or is there an electrical code related to tankless? as far as dedicated circuits? etc? 

As you guys can see, I am a full on plumber, not an electrcian, I can diagnose electric water heaters and such, but wireing and electrical code is beyond me  

I do know that if I remove a ground, put a new one on


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## Tankless (Jun 12, 2008)

CA uses the CEC...California Electric Code. it is basically a mirror copy of the 2005 NEC. Local ammendments apply just like all the trades.

2009 NEC says all exterior electrical devices must be GFCI protected....Code also stated that this appliance must have a means of disconnect. That is basically the extent of the code. A dedicated circuit is not required. However designated circuits like those for a kitchen / bathroom may not be "tapped" or branched. 
Gotta run


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## Tankless (Jun 12, 2008)

> I understand GFI's have to be installed in wet locations, this is fine, but that is if the unit is plugged into the GFI's, why not just put in a switch and a junction box? no plug, and don't wire the tankless through the GFI, so when the GFI pops, then the tankless goes off also.


Here is a line from the Noritz 751 OD Nat gas install manual (pg 16):

Breaker Installation:
Mount a device which shuts off the electrical path automatically (leakage breaker) when electrical leakage is detected.

To me that says install a GFCI...aka leakage detector. Wheather this is power in the form of a recept or a switched source...means absolutly nothing, the electricity itself must be GFCI protected.

Rinnai mentions nothing about GFCI protection, other than to install according to NEC and local codes.


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## Tankless (Jun 12, 2008)

So here's the deal,

If you choose to use a cord (pigtail) the rec must be GFI protected.
If you choose to put it on a switch GFI protection is not required.

That said,
I get a call at 6:50 this morning from a gut that has been without HW for 3 days. There was a power surge in his area a few days ago and he has no hot water. He also has a TV and dishwasher that blew out aswell. 

I get there, and the install is a mess, but it was operational. I find a burnt up internal GFI and a blackened power transformer. Inspected the mobo, nothing out of line but that doesn't mean there isn't damage.

Overnighted Sat delivery new parts, will post some pics. Reason I mention this is because all but one of the houses GFI's tripped. Being required and adding a layer of protection are two different things. I have done too many of these kind of repairs to know better. Needless to say I will be upgrading the electrical on this install. 

So thats the answer.


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