PDA

View Full Version : Electric Water Heater an Ignition Source?



Michael Waterbury
10-20-2007, 03:51 AM
Guys,

In an Inspection yesterday, I came across an electric water heater sitting on the floor of an attached storage room.
The International Residential Code states in P2801.6 that water heaters in garages with an ignition source be elavated 18" above the floor.
Is an electric water heater considered an ignition source?

I appreciate your advice

Bruce King
10-20-2007, 06:08 AM
The code is written in the gas water heater section. (this was info from an ICC certified inspector that I asked back in 2006 but now known to be incorrect)

It only applies to nat. or propane gas related ignition sources.

I have posted before that electric water heaters should be elevated but it is not required or enforced in this area.

But, if a loose wire inside of an electric water heater arcs, you now have an ignitiin source. Therefore, a writeup by an inspector is a valid point.

Michael Waterbury
10-20-2007, 08:02 AM
Thanks, Bruce

I recommended in my report that the heater be elevated. I would much rather be safe than sorry in this situation.

Jerry Peck
10-20-2007, 08:14 AM
To answer the question: "Is an electric water heater considered an ignition source?" ...

The answer is "Yes."

Electric water heaters ARE considered an ignition source. The terminals on the lower element arc (we've all seen arced up and burned up bottom element terminals as proof) and the lower thermostat is an automatic and unsealed switch which can arc (as any switch does).

From the IRC: (underlining is mine)


IGNITION SOURCE. A flame, spark or hot surface capable of igniting flammable vapors or fumes. Such sources include appliance burners, burner ignitions and electrical switching devices.

And, from the MECHANICAL section (not just Fuel Gas):


M1307.3 Elevation of ignition source. Appliances having an ignition source shall be elevated such that the source of ignition is not less than 18 inches (457 mm) above the floor in garages. For the purpose of this section, rooms or spaces that are not part of the living space of a dwelling unit and that communicate with a private garage through openings shall be considered to be part of the garage.

Jerry Peck
10-20-2007, 08:15 AM
The code is written in the gas water heater section.

It only applies to nat. or propane gas related ignition sources.

I have posted before that electric water heaters should be elevated also but I now know that it is not required.

But, if a loose wire inside of an electric water heater arcs, you now have an ignitiin source. Therefore, a writeup by an inspector is a valid point, just not supported by the codes.

It is supported by the codes, see my other post.

Brandon Chew
10-20-2007, 08:25 AM
The code is written in the gas water heater section.

It only applies to nat. or propane gas related ignition sources.

I have posted before that electric water heaters should be elevated also but I now know that it is not required.

But, if a loose wire inside of an electric water heater arcs, you now have an ignitiin source. Therefore, a writeup by an inspector is a valid point, just not supported by the codes.

My answer is based on the 2000 & 2003 IRC.

The code is written in the plumbing section.

"§P2801.6 Water heaters installed in garages. Water heaters having an ignition source shall be elevated such that the source of ignition is not less than 18 inches (457 mm) above the garage floor."

The commentary for the 2003 IRC says the term "ignition source" is intended to apply to all water heaters, and it was written that way to make it clear that it did not apply to only gas or oil fired water heaters (which have ignition devices).

So, to answer the original question, yes, the code section applies to electric water heaters. A thermostat or a switch opening and closing are some examples of an ignition source. But it is the ignition source, and not the bottom of the water heater that needs to meet the 18 inch requirement.

I noticed that the original question is for an attached storage room and not a garage, so elevation of the ignition source may not be required *by code*. However if common sense tells you that similar conditions may occur in the storage room as the garage (flammable vapors accumulating near the floor) then by all means mention it in your report.

(When I previewed this post, I saw that Jerry beat me to the punch, so I'm in good company)

Dom D'Agostino
10-20-2007, 08:29 AM
This issue comes around every 6-8 months. See the archived posts (http://www.inspectionnews.com/cgi-bin/ubb-cgi/forumdisplay.cgi?action=topics&forum=Plumbing+|AMP|+Water+Heating+Systems&number=11)for a ton of comments concerning that question.

My advice:
Contact your AHJ(s) in your work area, and discover what their interpretation of the code is for that particular issue.

Dom.

Jerry Peck
10-20-2007, 10:52 AM
My advice:
Contact your AHJ(s) in your work area, and discover what their interpretation of the code is for that particular issue.

But don't rely on their opinion if they say it is not an ignition source - they are wrong many times and more often than not will eventually correct themselves (with "eventually" being key).

Like when I moved up to Ormond Beach ... we bought this house a year ago December, closed on it a year ago last January, and had some things corrected before we moved up in July of that year. One of those things was raising the electric water heater up off the garage floor.

When I called a plumber to do it, they told me that I was the second person who told them that electric water heaters 'were considered ignition sources'. I asked who the other person was, the plumber responded 'at a continuing education class they had been to two weeks earlier'.

The word IS getting around, but it IS slow in doing so.

Thus, just because your AHJ 'has not yet heard', does not mean you should ignore the issue.

Richard Rushing
10-20-2007, 04:00 PM
Michael Waterbury stated:
"I came across an electric water heater sitting on the floor of an attached storage room."
_____________________

Here's the thing... if that storage room adjoins the garage with a common door (that opens to the garage), then yes... I'd say it needs to be elevated.

rr

Jerry Peck
10-20-2007, 06:19 PM
Michael Waterbury stated:
"I came across an electric water heater sitting on the floor of an attached storage room."
_____________________

Here's the thing... if that storage room adjoins the garage with a common door (that opens to the garage), then yes... I'd say it needs to be elevated.

rr

Unless the storage room floor is raised, then the height to the bottom element would need to be measured.

Michael Waterbury
10-21-2007, 03:54 AM
Jerry, the storage room floor is at the same level as the slab in the rest of the house.

Billy Stephens
10-21-2007, 05:57 AM
Guys,

In an Inspection yesterday, I came across an electric water heater sitting on the floor of an attached storage room.


Go Get Em Mikey!! :D

Frank Norman
05-22-2012, 07:36 AM
What about an electrical water heater below the floor level? Would an electric water heater that's 18 inches below the garage floor would be a problem? In the case I have in mind there is a crawl space below the part of the garage floor that has a wooden floor and the top of the water heater is 18 inches below the garage floor? The installation was approved by the electrical inpector.



Michael Waterbury stated:
"I came across an electric water heater sitting on the floor of an attached storage room."
_____________________

Here's the thing... if that storage room adjoins the garage with a common door (that opens to the garage), then yes... I'd say it needs to be elevated.

rr

Charles Harper
07-22-2012, 01:29 PM
Don't forget the exception of FVIR water heaters unless manufacturer required elevation.

Garry Blankenship
07-22-2012, 07:24 PM
Electric water heaters are not an ignition source any more than striking some steel or concrete with a mall. Both elements, ( the upper or lower designation is irelevant ), are emersed in water. You can surround that tank w/ the most flammable vapors you can muster and that water heater element is no threat. A / the thermostat could be, but I'm assuming it's location is above the heavier than air combustible vapors level, ( 18" ? ), so it's no thing. You can imagine "what ifs" forever because of the presence of electricity, but the unintentional ignition source like mentioned earlier is more likely an issue than an electric water heater.

Jerry Peck
07-22-2012, 08:26 PM
Electric water heaters are not an ignition source any more than striking some steel or concrete with a mall.

Ah, but they are. While some AHJ waffle on this issue, many AHJ understand and realize that they are ignition sources.


A / the thermostat could be, but I'm assuming it's location is above the heavier than air combustible vapors level, ( 18" ? ), so it's no thing.

That's one of the problems: the lower thermostat is not above 18" on any of the ones I've measured.

Are you telling me that you've never, ever, seen water heater element screws which have not burned and arced? They are also ignition sources, and they are also below 18" for the lower element on most electric water heaters.

Rich Goeken
07-23-2012, 05:16 AM
Electric water heaters are not an ignition source any more than striking some steel or concrete with a mall. Both elements, ( the upper or lower designation is irelevant ), are emersed in water. You can surround that tank w/ the most flammable vapors you can muster and that water heater element is no threat. A / the thermostat could be, but I'm assuming it's location is above the heavier than air combustible vapors level, ( 18" ? ), so it's no thing. You can imagine "what ifs" forever because of the presence of electricity, but the unintentional ignition source like mentioned earlier is more likely an issue than an electric water heater.

I would LOVE you to test your observation. Of course you can stand next to the heater, I will stand outside the house about 50 feet or more away. :)
Have you ever see a switch or relay break contact? There is a small spark---bigger spark if big load on circuit. There are "switches" in the control system of a water heater that are handling a lot of power---there WILL be a spark (big spark if inductive load). And so long as the air fuel mixture is about right, an explosion. However, I will not test my observations, sorry. :D

Stuart Brooks
07-23-2012, 08:12 AM
Another issue involving ignition sources that bothers me is an air handler in the same type of location as the garage utility closet in the above. In almost all cases I run across, the blower motor, a lot of wiring, and electronic control board are a foot or less above the floor and apparently no AHJ considers that an ignition source. Quite often there is also a filter slot in the return plenum. Not only is there an ignition source but also a fan sucking fumes into the HVAC circulation.

Jerry Peck
07-23-2012, 01:15 PM
Another issue involving ignition sources that bothers me is an air handler in the same type of location as the garage utility closet in the above. In almost all cases I run across, the blower motor, a lot of wiring, and electronic control board are a foot or less above the floor and apparently no AHJ considers that an ignition source. Quite often there is also a filter slot in the return plenum. Not only is there and ignition source but also a fan sucking fumes into the HVAC circulation.

Many AHJ do address that, as well as clothes washers and clothes dryers having ignition sources less than 18" above the garage floor, to name just two very common ignition sources which are often missed.

Garry Blankenship
07-27-2012, 09:32 PM
I would LOVE you to test your observation. Of course you can stand next to the heater, I will stand outside the house about 50 feet or more away. :)
Have you ever see a switch or relay break contact? There is a small spark---bigger spark if big load on circuit. There are "switches" in the control system of a water heater that are handling a lot of power---there WILL be a spark (big spark if inductive load). And so long as the air fuel mixture is about right, an explosion. However, I will not test my observations, sorry. :D

Gotcha Rich. It's why I mentioned the t-stat as a possibility, ( albeit very remote ). The height of that t-stat, how tightly sealed it ultimately is between it's own sealed enclosure and/or the tank exterior, ( they're pretty tight ), and the likely hood of a combustible mixture getting to it. All combined it would seem slim odds at best of an electric water heater causing an expolsion. Maybe a better web master than I could find out, if it has ever happened at all.

Stuart Brooks
07-28-2012, 08:33 AM
Gotcha Rich. It's why I mentioned the t-stat as a possibility, ( albeit very remote ). The height of that t-stat, how tightly sealed it ultimately is between it's own sealed enclosure and/or the tank exterior, ( they're pretty tight ), and the likely hood of a combustible mixture getting to it. All combined it would seem slim odds at best of an electric water heater causing an expolsion. Maybe a better web master than I could find out, if it has ever happened at all.

One also has to consider wiring and connections to the thermostat/switch. I have found burns from shorted wires that were pinched between metal pieces; connections that have overheated sufficiently to burn the insulation. I have to admit it is rare find for me but it does happen.

H.G. Watson, Sr.
07-28-2012, 10:04 AM
Depends...

See 500 (esp 500.5) of the 2008 NEC.

You may find the attached to be helpful as you begin to explore the subject matter.

HTH.

Garry Blankenship
07-30-2012, 10:16 PM
What does Article 500 have to do with a residential garage?

By precedent the code has established an 18" "classified" area by mandating gas water heaters be 18" off the floor. I'll leave the Class and Division up to you, but I'm thinkin a flammable zone is established, ( again by deault ). However; there are no similar requirements for any other devices that I know of. So a gas water heater burner must be 18" AFF, but a gas back packing stove or gas refridgerator or other not specifically named ignition source is fine on the floor ? In my world there are so many unlikely what ifs that must fall in place too create an "unintentional" garage explosion that the prevention efforts exceed the damage potential. Big brother is out of control on this :confused:

tom daley
08-04-2012, 05:29 PM
FWIW: The city of San Jose Ca. Building department has specific checklist requirements for water heaters, one requirement is for gas or electric water heaters to be raised 18".

AAMOI: their site is worth a visit for the pics and checklists and detailed, but straightforward, info.

Rich Goeken
08-05-2012, 04:50 AM
FWIW: The city of San Jose Ca. Building department has specific checklist requirements for water heaters, one requirement is for gas or electric water heaters to be raised 18".

AAMOI: their site is worth a visit for the pics and checklists and detailed, but straightforward, info.

Tom,
FWIW, AAMOI, AGGGG... some of us are old farts, and may not understand what you are trying to say without looking it up... :confused:
Notice VERY few here use this slang. Complete English sentences would be nice. :D

tom daley
08-06-2012, 04:45 AM
Rich,

A brief survey confined to the above posts reveals:
info. ICC. IRC. AHJ. FVIR. A/the. t-stat. NEC. and AFF.

Both of my abbreviations have often been used in this forum, and are in widespread use in most technical forums that I'm aware of; it's the sad nature of the beast - time is precious, expensive and short, hence abbreviations.

As a matter of interest, considered sentences dont require capitalised words to provide emphasis.

Thank you for taking an interest in my post.

Rich Goeken
08-06-2012, 05:19 AM
Rich,

A brief survey confined to the above posts reveals:
info. ICC. IRC. AHJ. FVIR. A/the. t-stat. NEC. and AFF.
Both of my abbreviations have often been used in this forum, and are in widespread use in most technical forums that I'm aware of; it's the sad nature of the beast - time is precious, expensive and short, hence abbreviations.
As a matter of interest, considered sentences dont require capitalised words to provide emphasis.
Thank you for taking an interest in my post.

Tom, never said they weren't used. Just suggested that if you could take the time to be clear to your audience---there may be less confusion. You may have missed this point in your enthusiasm to develop a list.

However, I am sorry that you are so busy that you can't take this time. I have witnessed situations where someone, so busy and similar to you, was using an acronym--others in the same conversation were also using it. However, when the conversation drifted in two directions, one person said "Wait, my definition of XXX is XXX. What is yours?" It seems the acronym was the same, but had two meanings. Wasted a lot of time with that.

From that time I don't use acronyms, only when necessary and not frivolous---just to make sure the thoughts I am offering are not confusing. You may do what you may, but I would like to leave you with this... Communications At Its Best, Is A Hazardous Process. :)

Jerry Peck
08-06-2012, 05:25 PM
A brief survey confined to the above posts reveals:
info. ICC. IRC. AHJ. FVIR. A/the. t-stat. NEC. and AFF.

Both of my abbreviations have often been used in this forum, and are in widespread use in most technical forums that I'm aware of; it's the sad nature of the beast - time is precious, expensive and short, hence abbreviations.


FWIW: The city of San Jose Ca. Building department has specific checklist requirements for water heaters, one requirement is for gas or electric water heaters to be raised 18".

AAMOI: their site is worth a visit for the pics and checklists and detailed, but straightforward, info.

"Both of my abbreviations have often been used in this forum"

They have? I know that FWIW stands for "for what it's worth", but I still do not know what to heck AAMOI stands for.

I agree that there is no need for the use texting short cuts - those came about when texting was charged by the charactor.

"it's the sad nature of the beast - time is precious, expensive and short, hence abbreviations"

If your time is that precious and expensive, then how about some consideration for ALL the time the REST OF US have to waste to read your posts? You save 10 seconds typing, 10,000 of us spend 1-10 seconds, sometimes longer, trying to figure what some of those things mean, but even at only 1 second each, that's 10,000 seconds spent just so you could save 10 seconds. There certainly is no economy savings of time there.

I supos thas why som dot bothr spelckig ethr, tme 2 precus. :rolleyes:

H.G. Watson, Sr.
08-06-2012, 11:12 PM
For the internet jargon challenged: AAMOI = As A Matter Of Interest.


Tom Daley: There are some here who consider anything other than cut and paste or clicking a preformatted link, effort. There are a particular few who will expend enormous effort, and spit out volumes of negative emotionally charged bilge in multiple cross posts whenever they are 'challenged' to exert a modicum of effort to acquire a bit of information that hasn't been spoon fed to their cut and paste brains or "quote button" convenience. Ignore them.

Garry Blankenship
08-07-2012, 07:53 AM
For the internet jargon challenged: AAMOI = As A Matter Of Interest.


Tom Daley: There are some here who consider anything other than cut and paste or clicking a preformatted link, effort. There are a particular few who will expend enormous effort, and spit out volumes of negative emotionally charged bilge in multiple cross posts whenever they are 'challenged' to exert a modicum of effort to acquire a bit of information that hasn't been spoon fed to their cut and paste brains or "quote button" convenience. Ignore them.

I will admit AAMOI was totally foreign to me. bilge is also new to me in the context used - - - is it anachronym for what a large male herbivore leaves behind ? A synonym perhaps ?

Aaron Miller
08-07-2012, 08:05 AM
I will admit AAMOI was totally foreign to me. bilge is also new to me in the context used - - - is it anachronym for what a large male herbivore leaves behind ? A synonym perhaps ?

bilge water 
noun
1.
Nautical . bilge ( def. 1d ) .
2.
Also called bilge. Slang . foolish, worthless, or offensive talk or ideas; nonsense; rubbish.

H.G. Watson, Sr.
08-07-2012, 11:36 AM
Word of the day: dictionary *. :eek: !!! (defined further below:rolleyes: ).

Garry,

You clicked over the quote reply button, waited for it to load, highlighted the word in the quote, then type-ity type-ity your unfamiliarity with the word, type-ity typeity your "guesses", implied the lower case word *might* be an acronym (!?!), and clicked submit reply!!!. All for what? Humor? Declaration of ignorance? Providing anecdotal evidence for a summarization contained in my earlier post?

It takes fewer motions of the hand or fingers, less time, less effort to simply open a new browser window, navigate to your favorite web search engine, and type "define:bilge" (without the quotes - note no spaces) or substituting whatever word you wish a definition of instead of "bilge" and institute a search. Results will include a multitude of high-ranking clickable links to a variety of free dictionary references on the internet - and likely the first definitions will appear truncated in your list of search results. Or for that matter one could type "acronym:AAMOI" for similar results.

Or you could have a free dictionary link saved in your favorites list.

dic·tion·ar·y [dik-shuh-ner-ee]
noun, plural dic·tion·ar·ies.

a book, optical disc, mobile device, or online lexical resource (such as Dictionary.com <http://dictionary.reference.com/>) containing a selection of the words of a language, giving information about their meanings, pronunciations, etymologies, inflected forms, derived forms, etc., expressed in either the same or another language; lexicon; glossary. Print dictionaries of various sizes, ranging from small pocket dictionaries to multivolume books, usually sort entries alphabetically, as do typical CD or DVD dictionary applications, allowing one to browse through the terms in sequence. All electronic dictionaries, whether online or installed on a device, can provide immediate, direct access to a search term, its meanings, and ancillary information: an unabridged dictionary of English; a Japanese-English dictionary.

Garry Blankenship
08-07-2012, 03:05 PM
Word of the day: dictionary *. :eek: !!! (defined further below:rolleyes: ).

Garry,

You clicked over the quote reply button, waited for it to load, highlighted the word in the quote, then type-ity type-ity your unfamiliarity with the word, type-ity typeity your "guesses", implied the lower case word *might* be an acronym (!?!), and clicked submit reply!!!. All for what? Humor? Declaration of ignorance? Providing anecdotal evidence for a summarization contained in my earlier post?

It takes fewer motions of the hand or fingers, less time, less effort to simply open a new browser window, navigate to your favorite web search engine, and type "define:bilge" (without the quotes - note no spaces) or substituting whatever word you wish a definition of instead of "bilge" and institute a search. Results will include a multitude of high-ranking clickable links to a variety of free dictionary references on the internet - and likely the first definitions will appear truncated in your list of search results. Or for that matter one could type "acronym:AAMOI" for similar results.

Or you could have a free dictionary link saved in your favorites list.

dic·tion·ar·y [dik-shuh-ner-ee]
noun, plural dic·tion·ar·ies.

a book, optical disc, mobile device, or online lexical resource (such as Dictionary.com <http://dictionary.reference.com/>) containing a selection of the words of a language, giving information about their meanings, pronunciations, etymologies, inflected forms, derived forms, etc., expressed in either the same or another language; lexicon; glossary. Print dictionaries of various sizes, ranging from small pocket dictionaries to multivolume books, usually sort entries alphabetically, as do typical CD or DVD dictionary applications, allowing one to browse through the terms in sequence. All electronic dictionaries, whether online or installed on a device, can provide immediate, direct access to a search term, its meanings, and ancillary information: an unabridged dictionary of English; a Japanese-English dictionary.



And you made it the motions it took to create the above for what - - - a pleasure that you you seem to derive from hurling insults. Text only does not always serve. I know what bilge is/means and your use of it amused me to the extent that I wanted to keep it alive. Your first guess on my "for what" / humor was correct. It obviously failed because Aaron thought I really needed help to look it up and because of your bilge packed post above. If I attempt any more humor, I'll try to consult you, ( his Duba-ya-ness ), privately for permission, content approval and post worthiness. In the interim, feel free to post as you see fit with the knowledge all will always approve at all times because you are the / His- Duba-ya-ness. The Duba-ya is the "W" in H.W. I looked it up in the dic-shun-ner-ee.

Jerry Peck
08-07-2012, 04:14 PM
Tom Daley: There are some here who consider anything other than cut and paste or clicking a preformatted link, effort. There are a particular few who will expend enormous effort, and spit out volumes of negative emotionally charged bilge in multiple cross posts whenever they are 'challenged' to exert a modicum of effort to acquire a bit of information that hasn't been spoon fed to their cut and paste brains or "quote button" convenience. Ignore them.

Tom,

As you can see from his posts in this thread, the thing that Watson is good at is attacking people and trying to insult them. Although I frequently return the favor when he does that.

Garry,

"His- Duba-ya-ness. The Duba-ya is the "W" in H.W. I looked it up in the dic-shun-ner-ee."

Very creative and humorus, the opposite of Duba-ya's pompassness. ;)

Got that from another dic·tion·ar·y [dik-shuh-ner-ee]: Urban Dictionary: pompass (http://www.urbandictionary.com/define.php?term=pompass) :)
- 1. pompass
- - one who is a pompous ass

Hey, don't get mad at us, Watson, it twas you who directed us to those dang dic·tion·ar·y [dik-shuh-ner-ee] thingys. :cool:

Rich Goeken
08-09-2012, 05:21 AM
Tom,

As you can see from his posts in this thread, the thing that Watson is good at is attacking people and trying to insult them. Although I frequently return the favor when he does that.

Garry,

"His- Duba-ya-ness. The Duba-ya is the "W" in H.W. I looked it up in the dic-shun-ner-ee."

Very creative and humorus, the opposite of Duba-ya's pompassness. ;)

Got that from another dic·tion·ar·y [dik-shuh-ner-ee]: Urban Dictionary: pompass (http://www.urbandictionary.com/define.php?term=pompass) :)
- 1. pompass
- - one who is a pompous ass

Hey, don't get mad at us, Watson, it twas you who directed us to those dang dic·tion·ar·y [dik-shuh-ner-ee] thingys. :cool:

Phew.... all this including insults, because someone was sooo busy that he couldn't take the time to be clear!!!:eek:

Bob Harper
08-09-2012, 05:54 AM
Good Morning Vietnam Acronym - YouTube (http://www.youtube.com/watch?v=H_aiDDU5z18&playnext=1&list=PL634CC49FC6BF3D64&feature=results_video)