Thread: gas water heater

what is going on here? notice the staining above the burner access door

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That staining is evidence of back-drafting. Force the heater to fire up and put a mirror down there - it will probably fog up. There are many reasons why this might be happening, from oversized flue to poorly inclined flue connector to blocked flue, etc. etc.

Maybe the fire extinguisher next to the tank is telling you something.

Yes backdrafting should be checked by a pro. Funny thing though is that usually if the unit is back drafting with the access door attached the door edges would be discolored also. They are not on this unit which leads me to believe that the home owner had to re light the pilot and left the access door off for a while. Maybe until those combustibles next to the unit started to smoke. Vis a vie the fire extinguisher.
You kind of have to look at these things like. Now what could I have done here "IF" I was just another stupid homeowner. Which I am, and things of this same stupid nature, I have done myself, even knowing the consequences.
So what can be expected of the general publi? Anything and everything.
This won't be the first time you see this so set up a boiler plate comment to key into your reports for this one.
Without the stupid homeowner comments for sure. HAHA Wayne

Also, looking at the pic again. If that garage door is left open. It is in the garage isn't it? And the door to the home has no auto closer. And the door were left open. The air pressure pushing into the home through the door would pull the flame right out of that unit causing the discoloration and possible asphixiation to the inhabitants of the home. The unit is also required to be be at least 16 inches above the floor level to prevent the gas can, set just out of view next to the fire extinguisher from exploding.

It should be 18 inches off the garage floor.

rick

Check this web-site out: Backdraft Interactions

Flame roll out may also be caused by improper oriface size, bad burner, bad control. Also, my guess is tghe inside cover isn't in place either.

Did you check inside to see if the stack dropped, creating a barrier to gases.
The exterior markings and the dropped stack seem to go hand in hand when ever I see it.

Peter. i did not but that is good to know for next time.

Was the flame in the gas burner yellow instead of blue, meaning out of tune? How old was the heater, it may be beyond its useful life. You could check for flue gas problems with a hand held combustible gas detector. This condition must be checked and corrected by a licensed plumber ASAP! The other comments about combustibles near the unit, height of the burner above the garage floor, and perhaps flex or copper gas piping penetrating the wall (not visible in the picture) are appropriate reporting for these conditions.

Evan Grugett

That galvanize gas pipe should be black pipe. Zinc coating flakes and particles can clog orifices.

Originally Posted by Mike Schulz

That galvanize gas pipe should be black pipe. Zinc coating flakes and particles can clog orifices.

I don't know that there is a prohibition against using galvanize pipe.

My brother in-law told me that. He does commercial HVAC. I just always figured it to be true because it's always been black pipe and flex.

Jim Z. said it best ALL gas water heaters at one point WILL have flame roll out due to poor maintnance. burners cake up with debree rust away. I do agree that backdraft could play a part but doutful in a garage if in a house just inside the door to a house i can see that from de-presureing the house when a door is opened.

Back when I was an engineer at a gas range component manufacturer, we had an AGA directive banning the use of zinc coated materials ( galvanized ) in products which would come in contact with natural gas. It is due to product liabilty / safety issues due to adverse chemical reaction of gas and zinc.

NFPA 54 "National Fuel Gas Code - 2006

Section:5.6.2.2 - Steel and Wrought Iron. Steel and wrought iron pipe shall be at least of standard weight (schedule 40) and shall comply with one of the following standards:

(1) ANSI/ASTM: B36.10 welded and seamless wrought steel pipe.
(2) ASTM A53, Standard specifications for pipe, steel, black, and hot-dipped, zinc coated welded and seamless.
(3) ASTM A106, Standard specification for Seamless carbon steel pipe for high-temperature service.

How strange,
If you google Galv gas pipe you will find mixed reviews. Some say yes some say no. All I know is that I never see it unless a home owner installs it. It makes sense to me not to use it because of the zinc. Maybe because of the diffrent grades of galv. that it's not used and because of not installing the right stuff.

How many of you guys out there use Galv. when you install pipes in homes? and why?

Originally Posted by Mike Schulz

How It makes sense to me not to use it because of the zinc.

Know those thingys (technical term) which never seem to get installed, or are installed incorrectly when they actually do get installed?

You know ...

... "Sediment Traps"?

Yeah, that's what they do ... catch that stuff, if any, and other 'stuff' to keep anything from happening.

Dark areas above the burner areas of water heaters sometimes indicates that the interior flame shield for the burner area has not been installed properly and is allow combustion gasses out of the front of the burner area. Check to see if the interior flame shield has been installed with the top metal section inside the burner area. Also, the heat coming from the burner area can damage the solenoid valve for the water heater. Check the operation of the solenoid valve to ensure it has not been damaged.

Don Merritt

By the way ...

Originally Posted by Jerry Peck

Know those thingys (technical term) ...

... "Sediment Traps"?

That 'thingy' in the photo was installed properly with the sediment trap leg down and the gas coming into it from the top.

Jerome:

John Arnold is giving you the best info.

This is also a sign of an older water heater that is near the end of it's life span. The heater most likey has burned out the bottom of the tank as noted in your picture of the leaking.



Rolland Pruner

Larry Brooks
Anniston, Alabama

Over the years I noticed the backdrafting around the access door in the photo and I bet it is a Rheem water heater.

Larry,

First, welcome to THE inspectors board.

Click on the 'User CP' link at the top left just under the 'Inspection News' logo and then 'Edit Profile', you can type your "Anniston, Alabama" there and it will show up at your 'Location' on your posts.

What I have heard about galvanized pipe used for gas pipe, is that galvanize has a tendency to flake off and clog up an orifice.

Originally Posted by Kenneth Koehn

What I have heard about galvanized pipe used for gas pipe, is that galvanize has a tendency to flake off and clog up an orifice.

"galvanize has a tendency to flake off and clog up an orifice"

Only if the *REQUIRED* "sediment trap" IS NOT installed.

I would list that on the list of "home inspector lore" as, if the sediment trap is installed as *required*, then that is not a concern, *even if* that flaking actually happens.

Nothing wrong with galvanized pipe.