Thread: 2015 UPC 608.3

Hi folks,

I read a recent thread on another bulletin board regarding the requirements for expansion tanks, PRVs and TPRVs. The thread was in regard to changes in the 2015 UPC which will be incorporated into the 2016 CPC, specific to tankless/flash water heaters and apparently came from IAPMO, but I have not been able to verify this independently as I cannot get onto the IAPMO website. Below is the original post from the other BB and at the bottom are my thoughts. (Bold/underlining are mine)

2015 Guide to Important Code Changes

608.3 Expansion Tanks and Combination Temperature and Pressure-Relief Valves

What Changed
608.3 Expansion Tanks, and Combination, Temperature and Pressure-Relief Valves. A water system provided with a check valve, backflow preventer, or other normally closed device that prevents dissipation of building pressure back into the water main, independent of the type of water heater used, shall be provided with an approved, listed, and adequately sized expansion tank or other approved device having a similar function to control thermal expansion. Such expansion tank or other approved device shall be installed on the building side of the check valve, backflow preventer, or other device and shall be sized and installed in accordance with the manufacturer's installation instructions.

A water system containing storage water heating equipment shall be provided with an approved, listed, adequately sized combination temperature and pressure-relief valve, except for listed nonstorage instantaneous heaters having an inside diameter of not more than 3 inches (80 mm). Each such approved combination temperature and pressure relief-valve shall be installed on the water-heating device in an approved location based on its listing requirements and the manufacturer's installation instructions. Each such combination temperature and pressure relief-valve shall be provided with a drain in accordance with Section 608.5.

Why It Changed
There is a misunderstanding throughout the industry that, if a tankless water heater is installed, an expansion tank is not necessary; this is not true except for instantaneous heaters having an inside diameter of not more than 3-inches. These small units having practically no storage capacity do not have significant thermal expansion. Other than this exception, the above revision clarifies that, regardless of the type of water heater that is installed, thermal expansion can still occur in the cold water supply line. Therefore, an approved expansion tank or other approved device needs to be installed.

What It Means To Me
This language addition indicates to the installer and inspector that expansion tanks and Temperature and Pressure relieve valves must be installed on every type of water heater that is installed, except for instantaneous heaters having an inside diameter of not more than 3-inches. Otherwise, thermal expansion can occur when water is heated no matter the type of heater used.

These water heaters are protected in three stages. The primary stage is the thermostat.

Should the thermostat fail, the secondary stage or highlimit switch will turn off the source of energy to the heater. If the high-limit switch fails, the combination T&P valve opens to prevent a catastrophic failure of the water heater. Instantaneous water heaters having an inside diameter of three inches or less are exempt from having a T&P valve. These small units are without a storage reservoir, having only a heating coil that does not allow significant thermal expansion. When the need for hot water has been met the instantaneous water heater shuts off. It does not cause a great amount of expansion because there is not a large volume of water to heat or expand.

When installing a T&P valve it is critical that the installer check the rating plate on the combination T&P valve before installation to make sure that the Btu input rating of the water heater does not exceed the maximum Btu rating of the valve. The use of an undersized combination T&P valve could result in a catastrophic water heater failure should both the water heater thermostat and the water heater high-limit switch fail. In instances where there are two separate Btu ratings on the valve plate, the smaller of the two is used in making this determination.

Manufacturers of T&P valves require that the valve be installed with its temperature-sensing element immersed within the top 6 inches of the tank since this is where the hottest water in the tank is located. Manufacturers recommend that they be manually opened at least once a year to ensure that they are functioning. In areas that have a high mineral content in the water, scale can form around the valve seat and render the valve inoperable. In such areas, it may be necessary to manually open the valve every three months or less. A water heater is a potential bomb that is prevented from exploding by three separate safety devices. The combination T&P valve is a lifesaver and is treated accordingly.

So, I am having trouble with the explanations (Why It Changed and What It Means To Me) seem to contradict the code. The way I read the first paragraph of 608.3 is the requirement for expansion tanks is regardless of the type of water heater. The second paragraph address the requirement for PRVs on tankless/flash water heaters with an interior diameter of 3 inches or less and a requirement for TPRVs on tankless water heaters with an interior diameter of greater than 3 inches.

In addition, when I searched online for help, I found interpretations that I cannot reconcile to the code or the explanations in the above text.

See p. 3 item #16 on the link below:
http://www.seattle.gov/dpd/cs/groups/pan/@pan/documents/web_informational/p2357861.pdf

See p. 11 on the link below.
http://www.wabo.org/assets/AEI/2016Handouts/2015%20upc%20wa%20state.pdf

By the way, has ANYONE seen a tankless/flash water heater with an interior diameter of 3 inches? I assume they are referring to the diameter of the heat exchanger tubing...

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Originally Posted by Gunnar Alquist

So, I am having trouble with the explanations (Why It Changed and What It Means To Me) seem to contradict the code. The way I read the first paragraph of 608.3 is the requirement for expansion tanks is regardless of the type of water heater. The second paragraph address the requirement for PRVs on tankless/flash water heaters with an interior diameter of 3 inches or less and a requirement for TPRVs on tankless water heaters with an interior diameter of greater than 3 inches.

I had to read and re-read that part a few times myself ... and it does state, unequivocally, "regardless of type" (okay, that might not be a direct and exact quote) that a thermal expansion valve is required - then it seems to turn itself around and say ... well ... except for ... in the reasoning section.

To me, someone is trying to re-write what it actually says, but the reasoning section will not be enforceable, only the actual code wording section is enforceable.

By the way, has ANYONE seen a tankless/flash water heater with an interior diameter of 3 inches? I assume they are referring to the diameter of the heat exchanger tubing...

I have not measured any of them.

Thanks Jerry,

I struggle enough reading code-speak and kept thinking I was missing something. I, too, read it repeatedly. The text that I posted seems to come from an IAPMO document/book titled "2015 Guide to Important Changes". I can't imagine why they interpreted their own code that way.
http://iapmomembership.org/index.php...emart&Itemid=3

I don't have the publication that I posted, so I cannot say for sure that it is verbatim, but I did find the same wording on a Linked-In post from an IAPMO representative.
https://www.linkedin.com/pulse/6083-...?trk=prof-post

I don't know if you followed the links, but the Seattle, WA interpretation really threw me. i saw nothing of that in the code.

I posted a question on the IAPMO site as well as to the rep on LinkedIn for clarification. IAPMO says I should hear back within 30 days. Good thing this isn't time-critical, huh? Maybe the rep will get back to me sooner.

Yes, I followed the links, the first one made as much sense as the article did.

Yeah, neither made sense to me. How could IAPMO interpret their own code in that way and then where did WA get hydronic systems out of something that made no mention?

Originally Posted by Gunnar Alquist

Yeah, neither made sense to me. How could IAPMO interpret their own code in that way and then where did WA get hydronic systems out of something that made no mention?

Maybe David Copperfield is on their staff?

(Had that 'so spaces with the space bar thing' again, put in a hard return with the enter key and the issue goes away - nice, quick, and easy fix ... not that is should be happening, but that is an easy fix.)

Good to know. I just ran into it myself as well. I assumed it was my computer, but maybe it's the website?

Originally Posted by Gunnar Alquist

Good to know. I just ran into it myself as well. I assumed it was my computer, but maybe it's the website?

Whatbrow (that 'no spaces with the space bar' thing again )

What browser are you using?

At first I thought it might have been an update to Chrome, but I'm now thinking it is this website.

At least the enter key stomps that bug out, but it is annoying to have to do that each time.

I have been using Chrome for quite a while now and have not run into this before. It hasn't done it on any other website either.

At least we now know how to fix it.

By the way, has ANYONE seen a tankless/flash water heater with an interior diameter of 3 inches? I assume they are referring to the diameter of the heat exchanger tubing...

Gunnar...the description may be referring to the instant hot water tank frequently installed inside kitchen cabinets with a spigot to provide instant hot water at the sink / wet bar instead of using the primary faucet. In fact I removed one just yesterday due to leaking. It's inside a metal casing measuring about 8"x 4".

Thanks Ian,

I had not thought of a hot water dispenser. That would make sense. It would also be helpful if the UPC could be more clear. Maybe I will get a response from IAPMO sometime this year.

Originally Posted by Gunnar Alquist

Thanks Ian,

I had not thought of a hot water dispenser. That would make sense. It would also be helpful if the UPC could be more clear. Maybe I will get a response from IAPMO sometime this year.

.....or not,

I'll dig the unit out the trash tomorrow and take a look inside.

Hope this helps, Gunner.
https://www.linkedin.com/pulse/6083-...-chris-sanchez

Originally Posted by ROBERT YOUNG

Hope this helps, Gunner.
https://www.linkedin.com/pulse/6083-...-chris-sanchez

Hi Robert,

Yeah, I saw that. It's exactly the same text as I posted (except for the strikeout and underlining) and has the same (apparently) erroneous explanation that I posted above. I already posted a question to Chris on that site, but have not yet heard back. I also sent a query to IAPMO with the same question. Their automated response let me know that I would hear back within 30 days.

Originally Posted by Gunnar Alquist

Hi Robert,

Yeah, I saw that. It's exactly the same text as I posted (except for the strikeout and underlining) and has the same (apparently) erroneous explanation that I posted above. I already posted a question to Chris on that site, but have not yet heard back. I also sent a query to IAPMO with the same question. Their automated response let me know that I would hear back within 30 days.

That's what I thought, Gunner.
What is the problem, Gunner? It is a precautionary component for water expansion.

I also looked into the types of memberships and pricing. I require further explanation before I going. Anyone know how the IAPMO membership structure is set up?

Originally Posted by ROBERT YOUNG

What is the problem, Gunner? It is a precautionary component for water expansion.

I thought I posted my questions clearly.

IAPMO's explanation for the code does not match the code. I believe the code says an expansion tank is necessary on a flash/tankless water heater, the explanation says it isn't. Wouldn't it be nice if the explanation matched the code?

Also, what does the 3-inch diameter refer to?

Originally Posted by Gunnar Alquist

I thought I posted my questions clearly.

IAPMO's explanation for the code does not match the code. I believe the code says an expansion tank is necessary on a flash/tankless water heater, the explanation says it isn't. Wouldn't it be nice if the explanation matched the code?

Also, what does the 3-inch diameter refer to?

You likely did to someone that understands it. Then there are the rest.
UPC 608.3: Any water system provided with a check valve, backflow preventer, or any other normally closed device that prevents dissipation of building pressure back into the water main shall be provided with an approved, listed, and adequately sized expansion tank or other approved device having a similar function to control thermal expansion. Such expansion tank or other approved device shall be installed on the building side of the check valve, backflow preventer, or other device and shall be sized and installed in accordance with the manufacture’s recommendation.

You express, "IAPMO's explanation for the code does not match the code."
Not trying to insinuate that you are incorrect but could you indicate what spastic article. Likely an amendment coming.

Originally Posted by Gunnar Alquist

Also, what does the 3-inch diameter refer to?

"There is a misunderstanding throughout the industry that, if a tankless water heater is installed, an expansion tank is not necessary; this is not true except for instantaneous heaters having an inside diameter of not more than 3-inches. "

That would be referring to the inside diameter of the heating vessel itself - the tube which the water is heated in, whether heated by gas blow torch cooking the outside of it or an electric element within it ...

Originally Posted by ROBERT YOUNG

You likely did to someone that understands it. Then there are the rest.
UPC 608.3: Any water system provided with a check valve, backflow preventer, or any other normally closed device that prevents dissipation of building pressure back into the water main shall be provided with an approved, listed, and adequately sized expansion tank or other approved device having a similar function to control thermal expansion. Such expansion tank or other approved device shall be installed on the building side of the check valve, backflow preventer, or other device and shall be sized and installed in accordance with the manufacture’s recommendation.

You express, "IAPMO's explanation for the code does not match the code."
Not trying to insinuate that you are incorrect but could you indicate what specifics to the article are you referring to? Likely an amendment coming.

One day shortly I will visit a local optometrist, but until then, my God these pharmacy opticals leave a lot to be desired when you read a post written by me.
Gees Louise. How do you all put up with me?

Well.... I just saw one of these in a remodel today. It is an electric tankless/flash water heater and the interior dimension is about 3" in diameter. This was the first electric tankless that I have seen. It was pretty nifty. About 18" square and low profile. Provided plenty of hot water to the bathrooms, but couldn't keep up with the tub and shower simultaneously. They do offer larger ones though.


No mention of pressure-relief valves. The installation instructions did state:


"Tankless water heaters such as the TEMPRA are not required to be equipped with a Pressure and Temperature Relief Valve (P&T). If the local inspector will not pass the installation without a P&T, it should be installed on the hot water outlet side of appliance"


http://www.stiebel-eltron-usa.com/si...all-tempra.pdf

Took a while to get an answer back from IAPMO regarding the article I posted. It seems my question became lost in their computer. I put my question in Century Gothic and their answer in Arial so the two could be more easily distinguished. I hope that makes it clear.


Gunnar,


This is the response to your request for clarification on the Uniform Plumbing Code. The question(s) considered was (were):


2015 UPC 608.3 The first paragraph states:
"A water system provided with a check valve, backflow preventer, or other normally closed device that prevents dissipation of building pressure back into the water main, independent of the type of water heater is used, shall be provided with an approved, listed, and adequately sized expansion tank or other approved device having a similar function to control thermal expansion. Such expansion tank or other approved device shall be installed on the building side of the check valve, backflow preventer, or other device and shall be sized and installed in accordance with the manufacturer's installation instructions.

Specifically, the wording: "independent of the type of water heater" is used. My understanding is that this would require an expansion tank on a plumbing system that has any type of water heater, including a "tankless/flash" water heater if there is a device that would prevent water pressure from equalizing by pushing back into the municipal or private water supply/service.

My problem is that in the "2015 Guide to Important Changes" (apparently published by IAPMO), under "Why It Changed", seems to state that instantaneous water heaters less than 3" in diameter are not required to have expansion tanks.

1. Which is correct?
2. Where does the 3" come from?

I see the reference in the second paragraph, but that refers to pressure and temperature/pressure relief valves.
The second paragraph of 608.3 describes the different requirements for pressure-relief and combination temperature/pressure relief valves on "listed non-storage instantaneous heaters having an inside diameter of not more than 3 inches (SO mm)".

3 What does the "3 inches" refer to?
4. Is this the tubing of the heat exchanger?

I am unaware of any residential "tankless/flash" water heating system that has tubing any larger than 3/4 inch.
My assumption is that this refers to a commercial-type boiler rather than something commonly found in a residence.

5. Is this correct?

Comment
Some online published information (from the State of Washington as well as "Guide to Important Changes") interprets the requirement for an expansion tank to mean an expansion tank is necessary only if the (tankless) water heater manufacturer requires an expansion tank and/or if this is a hydronic heating system. I do not see that in 608.3.

6. Is it elsewhere?

See p. 3, #16
http://www.seattle.gov/dpd/cs/groups/pan/@pan/documents/web_informational/p2357861.pdf
see p. 11
http://www.wabo.org/assets/AEI/2016Handouts/2015%20upc%20wa%20state.pdf


The UPC Answers & Analysis Committee answered as follows:
1. Based on 608.3, your understanding is correct. An expansion tank is required regardless of the type of water heater.


2. The exception for listed non-storage instantaneous heaters having an inside diameter of not more than 3 inches only applies to the requirement for an approved combination temperature and pressure-relief valve, it does not exempt an expansion tank.


Note: Non-storage instantaneous heaters are the small heaters designed to serve only one fixture, such as a lavatory or a bar sink and are not the same as tankless water-heaters that are meant to service the building’s entire hot water needs.


Sincerely,
John Roth,
UPC Answers & Analysis Committee


Request processed by,


Doug Kirk, Technical Services Supervisor


4755 East Philadelphia St
Ontario, CA 91761-2816
E-mail: doug.kirk@iapmo.org
Web: http://www.iapmo.org

I see that they answered the 3 inch size question as to what is the 3 inches ... NOT! Oh, well, at least they answered the main question.

Originally Posted by Gunnar Alquist

The UPC Answers & Analysis Committee answered as follows:
1. Based on 608.3, your understanding is correct. An expansion tank is required regardless of the type of water heater.

2. The exception for listed non-storage instantaneous heaters having an inside diameter of not more than 3 inches only applies to the requirement for an approved combination temperature and pressure-relief valve, it does not exempt an expansion tank.

An expansion tank, in California (under the UPC) is required for any type of water heater.

Note: Non-storage instantaneous heaters are the small heaters designed to serve only one fixture, such as a lavatory or a bar sink and are not the same as tankless water-heaters that are meant to service the building’s entire hot water needs.

So ... a tankless is not always a tankless ... it depends on how it is used?

Put a monster tankless in for the entire house, it is a tankless (non-storage) water heater which requires an expansion tank.

Put a monster tankless (non-storage) water heater in for the bar sink and it does not require an expansion tank. I know, they were referring to those small one-fixture things found in kitchens and wet bars, as well as many restrooms where there is no water heater (gas stations and the like).

Jerry,

I infer (possibly incorrectly) that my question regarding the 3" diameter was answered by the note about single-fixture water heaters, but I would have preferred that be made clear with a statement like: "The 3" diameter refers to single-fixture water heaters".

Anyway, it's nice to know I can accurately read code. It is a little distressing that IAPMO's clarification was wrong.