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OR- water heater discharge pipe codes


Brandon Whitmore

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Do any of you Oregon guys have the history of code changes regarding water heater discharge pipe clearances from the ground? Specifically, in a garage when plumbed to the slab floor. I'm looking for a history for the last 20 years if possible....

2011: between 6-12" of the ground.

2008: Strange wording-- I don't really know based on chapter 6

2005:?

2002:?

1999:?

1996:?

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Do any of you Oregon guys have the history of code changes regarding water heater discharge pipe clearances from the ground? Specifically, in a garage when plumbed to the slab floor. I'm looking for a history for the last 20 years if possible....

2011: between 6-12" of the ground.

2008: Strange working-- I don't really know based on chapter 6

2005:?

2002:?

1999:?

1996:?

I can look, but first where are you getting teh 6" - 12" numbers from? It looks more like 6"- 24" to me. (608.5)

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I got the 6-12" from the 2011 version.

608.5 is where I looked.

See here 608.5 #3 : 2011

The 2008 version isn't very clear. For exterior termination points, the discharge pipe must be between 6-24" from the ground, or greater than 16' from the ground. Other Approved Locations doesn't specify the height. I'm assuming this caused some issues, and is the reason behind the change to the 2011 version??

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Do any of you Oregon guys have the history of code changes regarding water heater discharge pipe clearances from the ground? Specifically, in a garage when plumbed to the slab floor. I'm looking for a history for the last 20 years if possible....

2011: between 6-12" of the ground.

2008: Strange wording-- I don't really know based on chapter 6

2005:?

2002:?

1999:?

1996:?

Well, the first thing is says, in 505.6 is that the valves have to be installed per their listing and instructions. Every one that I've seen says that the discharge line must be "as short as possible" and "terminate at least 6" above a drain." So, to comply with these instructions, literally, you'd need a discharge line that was a few molecules long, or as short as you could possibly make it.

That fancy aside, the instructions seem to prohibit anything less than 6" at the bottom of the line. They're, no doubt, concerned about a cross connection. So, if we were on the IRC, I'd say that the discharge pipe would have to end *exactly* 6" above the floor.

That said,

2008: As you know, it says from 6" to 24" outside, but the following sections seem to assume that the same distances apply to the other approved locations on the list.

2005: The same as 2008.

2002: In the Water Heater section, it says that the water heater has to be equipped with "a combination temperature and pressure relief valve." In the pressure-relief valve section, it says basically the same thing that the 2008 edition says.

1999: Same as 2002.

1996: Same as 1999.

1993: It just says, "The discharge pipe shall not be smaller than the relief-valve outlet, shall not be trapped, and shall terminate with an air gap into a plumbing fixture, floor drain, or other suitable point of discharge.

1990: Same as 1993.

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I'd say that if the installation instructions are supposed to be followed, it would be improper to have the discharge pipe be any *closer* than 6" to the floor.

I went to Watt's website before posting. One of their last sentences states that where the installation instructions differ from local code, that the local code needs to be followed.

Thanks a bunch for the archived list.

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I'd say that if the installation instructions are supposed to be followed, it would be improper to have the discharge pipe be any *closer* than 6" to the floor.

I went to Watt's website before posting. One of their last sentences states that where the installation instructions differ from local code, that the local code needs to be followed.

Thanks a bunch for the archived list.

Yeah, they don't want the liability of telling you where to run the discharge. They're only real concern is that the valve not be obstructed in a way that would prevent it from working properly.

Personally, I'm fine with the tube ending anywhere below knee level. For all the discussions that home inspectors have about this topic, I can't remember ever hearing about anyone getting scalded by a TPR valve that was plumbed two or three feet off the floor.

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The reason for this post was that one of my buddies at my day job wrote " extend discharge pipe within 6" of the ground" and got written up by QA for providing improper info. I was digging for something that would have exonerated him since it was an older installation.

QA wrote him up, and provided the wrong info. as well......

Our job depends on our annual QA scores.

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Who monitors the QA guys?

Great question that has recently been discussed. One of the tech's said that he'd love to be the QA's QA guy.

Basically, if we disagree with a QA write up, we must discuss the issue with our supervisor. If the supervisor agrees with us, he pushes to get the points back.

In most cases, I've found the QA guys to be pretty fair. On this one, I disagreed w/ QA and tried to get the points back for my buddy. He wrote that the discharge pipe should be within 6" of the ground, while the QA guy said he was wrong and that it was within 18".

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