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Rich Sumen
05-12-2011, 12:52 PM
Does anyone know if there any exceptions to the "18 inch high" rule on gas burners / appliances in a garage?
This is a newer, sealed burner type gas water tank, about 4" up from the floor, in a garage side closet area (Open to that garage).

I just was not sure if there was an exception for these but I dont think so.
Thanks in advance.

Rich

Ray Norton
05-12-2011, 01:32 PM
That does not look like it has a sealed combustion chamber. I wish I could see the whole water heater. Water heaters of that type don't have vent openings like that and would have 2 pipes to the exterior. But to answer your question: If combustion air is not obtained from the garage and the combustion chamber is sealed or the closet is sealed from the garage the location would be OK. You need to take a look at the manufacturer's specs.

Jim Robinson
05-12-2011, 02:36 PM
He's talking about an FVIR type water heater. Some areas are allowing them on the slab instead of raised up 18". You'll have to check in your area, Ray, to see if the AHJ is allowing them on the floor.

Rich Sumen
05-12-2011, 02:46 PM
No sorry, This unit does take in air for combustion.
One flue pipe, at the top, into a chimney.
It is however the newer "sealed type" burner.
(No access to the burner area)

I guess I just had a brain freeze. It is clearly taking in air, at the
bottom vents, so I'm sure it must comply with the 18" rule.

Thanks guys!

Jim Robinson
05-12-2011, 03:10 PM
This was posted here in March.


2006 IRC

G2408.2 (305.3) Elevation of ignition source.

Equipment and 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 hazardous locations and public garages, private

garages, repair garages, motor fuel-dispensing facilities and
parking 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 directly with a private garage through openings
shall be considered to be part of the private garage.


Exception:

Elevation of the ignition source is not required
for appliances that are listed as flammable vapor ignition

resistant.

Dom D'Agostino
05-12-2011, 03:25 PM
It is clearly taking in air, at the
bottom vents, so I'm sure it must comply with the 18" rule.

Thanks guys!

FWIW:

FVIR style appliances are typically exempt, depending on the AHJ in your locale.

Rheem talks about them here (http://www.google.com/url?sa=t&source=web&cd=2&ved=0CEsQFjAB&url=http%3A%2F%2Fwaterheating.rheem.com%2Fcontent% 2Fresources%2Fdocuments%2Ftech%2520bulletins%2F140 0%2520Series%2F1418.pdf&rct=j&q=fvir%20water%20heater%2018%20inch&ei=31zMTantCpGXtwfJ9rWVBQ&usg=AFQjCNF4LA3fsfm0G0muz2yQ2ldXWaFogA&cad=rja)

John Kogel
05-12-2011, 05:40 PM
I went thru this whole scenario about a month ago. The AHJ for one area I inspect in is now allowing FVIR water heaters to sit flat on the ground. The water heaters are the same units that last year needed to be elevated, this year, they do not. :confused:
Some tanks carry the old decals, saying danger, keep flammables away, elevate the WH, etc. The factory rep said this is a mistake, all the units they have produced in the last 5 years have been safe to set on the floor.

Ted Menelly
05-12-2011, 06:11 PM
I went thru this whole scenario about a month ago. The AHJ for one area I inspect in is now allowing FVIR water heaters to sit flat on the ground. The water heaters are the same units that last year needed to be elevated, this year, they do not. :confused:
Some tanks carry the old decals, saying danger, keep flammables away, elevate the WH, etc. The factory rep said this is a mistake, all the units they have produced in the last 5 years have been safe to set on the floor.


They all take in combustion air from the level of the floor and not higher up so I just do not see how they can tag them "safe" to sit on the floor with combustible fumes all around it.

Jim Luttrall
05-12-2011, 06:44 PM
They all take in combustion air from the level of the floor and not higher up so I just do not see how they can tag them "safe" to sit on the floor with combustible fumes all around it.

Kind of a one way valve, air goes in but flames don't go out.


What is FVIR? It means Flammable Vapor Ignition Resistant. A new ANSI (American National
Standards Institute) standard will go into effect that will prevent a water heater from igniting flammable
vapors outside the combustion chamber.

John Kogel
05-12-2011, 07:18 PM
They all take in combustion air from the level of the floor and not higher up so I just do not see how they can tag them "safe" to sit on the floor with combustible fumes all around it.Actually, the direct vent units draw combustion air down from outside.

Wayne Carlisle
05-13-2011, 06:19 AM
In the picture it looks like the WH is inside a closet. Is there a door on the room? If so...all may be mute!

What about protection from impact IF it is not inside a room?

Kevin O'Hornett
05-13-2011, 08:52 AM
FVIR technology utilizes several new design features. Instead of having combustion air enter the combustion chamber as it does in a conventionally aspirated unit, combustion air enters the combustion chamber through special inlets at the base of the water heater or on the side of the water heater.

It then passes through a finely perforated plate called a flame arrestor which allows it to be evenly distributed to the burner where it’s mixed with the fuel gas and the mixture is ignited by a pilot device.


The function of the flame arrestor is to create a one way path for flames. The air holes or slots in flame arrestor plates are designed so that the velocity of the airflow entering the combustion chamber through the arrestor is higher than the flame speed of any vapors that are ignited in the combustion chamber.

This prevents flashback out of the combustion chamber. In the event that flammable vapors are drawn into the combustion chamber along with the combustion air and are ignited, the flames are unable to escape back down through the fine openings in the arrestor and the vapors burn off harmlessly on the top surface of the flame arrestor.

To reduce the potential for clogging the fine perforations in the flame arrestor, FVIR water heaters are equipped with filter screens, baffled combustion air ducts, or other design elements to trap the lint, dust, and oil (LDO) that are often present in the air in garages, laundry rooms, basements, and other areas in which water heaters are often located. If an arrestor plate becomes obstructed by LDO or other contaminants, it can reduce or cut off the combustion air resulting in improper combustion and the production of carbon monoxide and soot.

In addition, there is a thermal cut-off device in the combustion chamber which automatically shuts off the gas supply to the burner and pilot when it senses excessive temperatures that are generated when flammable vapors ignite inside of the combustion chamber or when LDO filters become clogged.

If an FVIR unit is installed with a collection pan, there must be sufficient
clearance between the water heater and the sides of the pan to prevent
obstruction of combustion air flow and the heater itself must be raised high
enough above the flood level or drain outlet of the pan to prevent immersion
of the combustion air inlets.

Rheem / Ruud manufacturing incorporates an additional technology into their
FVIR water heaters. Rheem / Ruud recognized that while a flame arrestor is
designed to prevent ignition of vapors outside of the combustion chamber, it
does not prevent a sustained flammable vapor event in which the vapors
continue to burn inside of the combustion chamber.

To address this issue, in addition to shutting off the gas when there is a vapor
ignition event in the combustion chamber, Rheem / Ruud FVIR water heaters
also shut off the combustion air supply at the same time.

Ted Menelly
05-13-2011, 09:51 AM
Filters, sensors, mechanical devices that can all foul in one way or another. Put the damn thing 18 inches off of the floor anyway and forget about it ..... but clean those filters

Wayne Carlisle
05-13-2011, 09:52 AM
Filters, sensors, mechanical devices that can all foul in one way or another. Put the damn thing 18 inches off of the floor anyway and forget about it ..... but clean those filters

DITTO!!

brian schmitt
05-13-2011, 11:32 AM
DITTO!!
when the next diy replaces that wh what guarantee is there that he will use a fvir rated heater?

Richard Poole
05-13-2011, 03:53 PM
The city building dept. where I live still requires the 18" minimum even on FVIR heaters.

paul hardy
05-13-2011, 06:22 PM
when the next diy replaces that wh what guarantee is there that he will use a fvir rated heater?

They only manufacture FVIR water heaters it was mandated by the goverment to include this technology on all water heaters.

John Kogel
05-13-2011, 09:23 PM
Filters, sensors, mechanical devices that can all foul in one way or another. Put the damn thing 18 inches off of the floor anyway and forget about it ..... but clean those filtersWell that is what I said, brand new home deficiency lit. Builder siad "No, I don't have to, because the authority allows it to sit upon the garage floor."

Roger Hankey
05-16-2011, 04:32 AM
Filters, sensors, mechanical devices that can all foul in one way or another. Put the damn thing 18 inches off of the floor anyway and forget about it ..... but clean those filters

What is the cost/benefit analysis that would make you recommend that this be done when it meets the manufacturer's installation requirements. They paid extra to get the FVIR model, when pay more to put it up for little or no benefit. The screens - filters need to be cleaned regardless of location.

Were you simply suggesting an ideal, or making a recommendation for the inspection report? If for the report, when you make one recommendation for unrequired improvements, why not have other or ALL components upgraded to ideal? Where do you stop?

It seems to me that we need to be very careful about what we recommend to our fellow inspectors, and what we recommend to our customers. This is why I occasionally use the term ELECTIVE MODIFICATION for remarks to suggest a change to better than required, or ideal conditions.

Wayne Carlisle
05-16-2011, 08:52 AM
Well that is what I said, brand new home deficiency lit. Builder siad "No, I don't have to, because the authority allows it to sit upon the garage floor."

The authority may have allowed it but the "code" probably didn't!

Just because the AHJ allows something does not make it "law".

Ted Menelly
05-16-2011, 12:58 PM
What is the cost/benefit analysis that would make you recommend that this be done when it meets the manufacturer's installation requirements. They paid extra to get the FVIR model, when pay more to put it up for little or no benefit. The screens - filters need to be cleaned regardless of location.

Were you simply suggesting an ideal, or making a recommendation for the inspection report? If for the report, when you make one recommendation for unrequired improvements, why not have other or ALL components upgraded to ideal? Where do you stop?

It seems to me that we need to be very careful about what we recommend to our fellow inspectors, and what we recommend to our customers. This is why I occasionally use the term ELECTIVE MODIFICATION for remarks to suggest a change to better than required, or ideal conditions.

Count the items changed to allow it to be sitting on the floor of a garage..

As far as what is working today and what is going to work tomorrow or what might be safe today and what might be safe tomorrow. it was always a foolish idea to set the water heater directly on the floor. I guess I cannot be any more direct than that

A pan under the unit so you can run a drain line out the side wall instead of running the leak across the floor and damaging goods that are stored in the garage, filters clogging, auto gas shut off fails.

They should have made it safer and still recommend it be off the floor.

It is still my recommendation that that they raise it off of the floor. Whether it be code or not code a recommendation is just that, a recommendation.

Like I said, write it up anyway as a recommendation with a reasonable explanation on why it is being written up.

As far as a recommendation to other inspectors, well, it is still just that, a recommendation. They can do as they wish.

Also sitting up off the floor always makes it safer from minor bumps and such or gas lines exposed at lower levels, having to add further protection such as a posts so it does not get bumped by a bumper.

As far as a cost analysis? Not sure what you mean. A cost analysis of building a small platform in the garage ? ... next to nothing.

John Kogel
05-16-2011, 03:22 PM
I called for it to be elevated. So if or when it gets hit by a car, it won't be my ass in a sling. :confused:

PS, don't bother posting that it needs a bollard or bulwark or whatever. We already discussed this one back in March.

Roger Hankey
05-16-2011, 09:44 PM
This link:

http://charmeck.org/mecklenburg/county/CodeEnforcement/Mechanical-Plumbing/Documents/FVIR%20garage%20install_r2%20rheem.pdf

contains letters from Rheem/Ruud and State water heater companies wherein they indicate that FVIR type water heater may be installed on the floor of a garage.

Roger Hankey
05-16-2011, 09:52 PM
AO Smith installation requirements for FVIR heaters are at:
http://www.managemylife.com/mmh/lis_pdf/OWNM/L0906086.pdf

Jerry Peck
05-17-2011, 05:24 PM
What is the cost/benefit analysis that would make you recommend that this be done when it meets the manufacturer's installation requirements. They paid extra to get the FVIR model, when pay more to put it up for little or no benefit. The screens - filters need to be cleaned regardless of location.

Were you simply suggesting an ideal, or making a recommendation for the inspection report? If for the report, when you make one recommendation for unrequired improvements, why not have other or ALL components upgraded to ideal? Where do you stop?

It seems to me that we need to be very careful about what we recommend to our fellow inspectors, and what we recommend to our customers. This is why I occasionally use the term ELECTIVE MODIFICATION for remarks to suggest a change to better than required, or ideal conditions.

Roger,

Not sure if you are promoting a "minimalist"type of reporting or not ... but that is what it seems to me when people say we should give less information and write things up in a supposedly "non-alarmist" way using phrases such as "ELECTIVE MODIFICATION".

Anyway, while I may think some go too far, others may think I go too far, and the home inspector needs to find out what works for "them" and use that.

Roger Hankey
05-17-2011, 09:49 PM
Roger,

Not sure if you are promoting a "minimalist"type of reporting or not ... but that is what it seems to me when people say we should give less information and write things up in a supposedly "non-alarmist" way using phrases such as "ELECTIVE MODIFICATION".

Anyway, while I may think some go too far, others may think I go too far, and the home inspector needs to find out what works for "them" and use that.

I am not one of those who say we should give less information. I write reports in a neutral voice. Go back to what I said about Elective Modification. I do not use that term when adverse conditions are found.

I do not believe home inspection and report writing is as subjective as your remark suggests. Once the terms in the report are carefully defined, the conditions found can be assigned a recommendation objectively based on those underlying definitions.

Typically, the adverse condition is briefly described, and the recommendation is "immediate correction by a qualified (tradesperson category)". Ex: The kitchen sink drain is not vented. RECOMMENDATION: Have the sink drain corrected ASAP by a qualified plumber. The introduction of the Plumbing section would list typical consequences of improper plumbing, such as leaks, water damage, unsanitary or unhealty conditions (including contamination of drinking water), and the potential for sewer gas entry.

Brevity of language is not a "minimalist" inspection technique, rather it is a desireable reporting style. I inspect carefully and report all the adverse conditions I find. The point of my remarks in this thread was to counter the claim that an FVIR water heater must be raised off the floor. Clearly they do not, except in cases where AHJ has rules different than many manufacturers requirements.

Zibby Bujno
05-23-2011, 08:49 PM
What with that AC coil on the floor?

Ron Hasil
05-23-2011, 09:25 PM
All gas water heaters sold up to 65 gallon heaters are FVIR 75 gallon units are still standard open combustion chambers. Also all FVIR heaters will and must have the keep flammable liquids and vapors away from the heater sticker still.

If flammable vapors enter the heater they burn off in the unit and will not send a spark or flame out of the burn chamber. But here is where the issues happen as its is burning off the flammable vapors which is burning below the normal burner they have a sensor that will trip and turn the heater off, in on form or anther. Rheem does this by a glass vial that shatters and a spring door slams shut choking the heater off from its combustion air, A.O Smith and State are one in the same for the last 5 years, they suck the air from the bottom of the heater (bad idea in my mind) but use a thermal switch that is resettable. Bradford white draws its combustion air from the sides (better design in my mind) and also uses a thermal switch, so when these units have the vapors burning off the thermal switch will trip and kill the pilot.

The reason I do not like the way State and A.O smith draw in its combustion air is its like a vacuum cleaner sucking all the dirt and dust . Yes they have a filter but it just does not do the job. I have ran into 100's of these heaters where the fine mesh screen in the heater is clogged , and all the cleaning of it just never gets it back to normal operation.

So when I install these FVIR heaters in a garage they still are on an 18" platform.

Ron Bibler
05-24-2011, 09:05 AM
"HOT WATER HEATER" ? OR Water Heater. That is the question.

Best

Ron