Tie PEX into water pipes at water heater? Hows this look?

[Cacher_Chick]

Hackney, It good to see you are becoming educated.

Keep at it.

UPC Code 604.11.2 Water Heater Connections. PEX tubing shall not be installed within the first eigthteen (18) inches (457 mm) of piping connected to a water heater

 

[Hackney plumbing]

Hackney, It good to see you are becoming educated.

Keep at it.

Yeah i'd hate for my hot water in the top of the tank to melt my pex. LOL Glad we cleared that ignorant statement up.

 

[Sponsor]

 

[Jadnashua]

Yeah i'd hate for my hot water in the top of the tank to melt my pex. LOL Glad we cleared that ignorant statement up.

The code is apparantly written for all WH. It's not the water, generally, but the flue on a gas WH that can get quite hot. But, if the safety circuits failed, before the T&P opened, the water temperature could easily be above the max value allowed for plastic pipe. If it is separated some, natural radiation will help lower those temps when copper is used to connect. As said earlier, it appears that the code is written generically for WH installation, regardless of type. Could it differentiate, possibly, but the codes are written for those what-if situations, not the generic, normal situation. they don't want it to fail with a typical failure path, and a failed thermostat that allowed the water to get to the point where the T&P opened, is one of them.

the codes are written and updated based on the collective experience of a huge number of situations, updated materials choices, and inputs...if you really think your one opinion is better than that, petition to have it changed, and see, if it has merit, there's a chance. Until then, the terms of your license dictate doing it per code.

UPC Code 604.11.2 Water Heater Connections. PEX tubing shall not be installed within the first eigthteen (18) inches (457 mm) of piping connected to a water heater

 

[Hackney plumbing]

The code is apparantly written for all WH. It's not the water, generally, but the flue on a gas WH that can get quite hot. But, if the safety circuits failed, before the T&P opened, the water temperature could easily be above the max value allowed for plastic pipe. If it is separated some, natural radiation will help lower those temps when copper is used to connect. As said earlier, it appears that the code is written generically for WH installation, regardless of type. Could it differentiate, possibly, but the codes are written for those what-if situations, not the generic, normal situation. they don't want it to fail with a typical failure path, and a failed thermostat that allowed the water to get to the point where the T&P opened, is one of them.

the codes are written and updated based on the collective experience of a huge number of situations, updated materials choices, and inputs...if you really think your one opinion is better than that, petition to have it changed, and see, if it has merit, there's a chance. Until then, the terms of your license dictate doing it per code.

So 18" of copper saves the day. Think about that for a minute. One guy says hot water will melt the pex...now you say its because the water heater may malfunction. Sure thats why the water heater has high limit cut outs if the thermostats fail electric or gas. I assure you 18" of copper isn't going to protect pex if the heater malfunctions.

Who says I'm not doing my work to code? Do you really think the code is the final say? I can have a licensed enginneer sign off on alternate plumbing systems and tell the inspector to find another job to thump his code book on.

A cold vent when a gas water heater fires gets hot at the draft diverter and the immediate pipe at the start of the vent. As the vent heats up and the draft starts to flow it cools back down. Thats why they do not want it connected to a gas fired heater unless the heater has side inlet connections.

Show me one official document that says pex needs to be 18" from the heater to protect the pex if the water heater malfunctions. You cant do it.

 

[Hackney plumbing]

What do you supose the heat loss is of an 18" piece of copper that could be insulated would be? The code doesn't say you cant insulate the copper.

If the code intended the 18" of copper to be a "heat dump" they wouldn't allow you to insulated it.

Further more......I was informed in a previous post that the hotest water in the heater is at the top. I totally agree with that. So if you have 18" pieces of copper vertical rise from the top of the heater,where do you suppose the hottest water will be? again whats the heat loss of an 18" piece of copper.

I have another question for you. What if the T&P valve fails to open. Would you rather have a heater with 18" of copper between your pex or would you want pex directly to your electric water heater?

Are you going to rely on the 18" of copper to "cool" the water down? Remember the code is written for the "what if's" as you say.

 

[Jadnashua]

If the thermostats have failed, and the T&P won't open, you won't have to worry about what's installed as it is all going to blow up.

The goal is to protect the plastic pipe from the gas WH flue. The code (apparantly) doesn't differentiate as to the type of the WH, so if it says 18" of copper to the transition, you put 18" to the transition...petition the code people to change that if you wish, until then, follow the code. Failed thermostats could also allow the water to get hotter than is allowed for the piping, which might be a factor in their thoughts, but I do not know. Feel free to take it up with your local inspector and petition to have the codes ammended...

 

[Hackney plumbing]

If the thermostats have failed, and the T&P won't open, you won't have to worry about what's installed as it is all going to blow up.

The goal is to protect the plastic pipe from the gas WH flue. The code (apparantly) doesn't differentiate as to the type of the WH, so if it says 18" of copper to the transition, you put 18" to the transition...petition the code people to change that if you wish, until then, follow the code. Failed thermostats could also allow the water to get hotter than is allowed for the piping, which might be a factor in their thoughts, but I do not know. Feel free to take it up with your local inspector and petition to have the codes ammended...

Why do you think every code everywhere prevents the installation of pex to an electric water heater? It doesn't and some places I do plumbing the code has no authority to even step on the property. You really think the U.S. goverment gives two craps what some honky tonk inspector says? He'd nevr make it on the base.....

This is about whats technically right and whats wrong.....not what a code book says. Now that every theory you guys have had is not holding water(no pun intended) the old standby comes out....."The code says so" LOL

UPC Code 604.11.2 Water Heater Connections. PEX tubing shall not be installed within the first eigthteen (18) inches (457 mm) of piping connected to a water heater

 

[Hackney plumbing]

You guys act like I'm telling you the world is flat. I never said it wasn't a code anywhere.

When you learn the reasons for codes is when you become a better plumber. Thats all i was discussing is WHY. I got answers from the water melting pex to the water heater malfunctioning and then finally because the code says so.

Ok I think I've made my point and laid out some knowledge and the references for it. Just like that 6' long trap weir I posted.....when a large corporation comes to town and wants to build somthing a certain way.....the code book is thrown out the window. Politics come into play. Dont ever think the code is not influenced by politics because it is just like everything else.

 

[Terry]

Hackney,
When a home owners asks if it's okay to do something, they are not asking for "Hackney's" permission, they are asking if a plumbing or home inspector will approve it. There is insurance liability to be concerned with too. If a homeowner has installed something out of "code", does the insurance pay off?

We try to answer questions here with the intention that wherever the installation is, that it will "pass" a plumbing inspection.
This is why I require a location by state or province so we have a better idea as to how to better answer the questions.

 

[Hackney plumbing]

Hackney,
When a home owners asks if it's okay to do something, they are not asking for "Hackney's" permission, they are asking if a plumbing or home inspector will approve it. There is insurance liability to be concerned with too. If a homeowner has installed something out of "code", does the insurance pay off?

We try to answer questions here with the intention that wherever the installation is, that it will "pass" a plumbing inspection.
This is why I require a location by state or province so we have a better idea as to how to better answer the questions.

I totally agree and would never tell a homeowner to violate their local code. I didn't do that on this thread and never implied it.

To answer your question about the insurance paying off,yes they will. if they didn't half the claims they process wouldn't get paid around here. I've delt with insurance companies thousands of times and they have never asked me if the plumbing was "to code" Not yet anyway. I agree with you they should tho.

 

[Jeepnick]

Although I hesitate to re-enter my own thread, I was reading the tangent topic and had a thought. Wouldn't the 18" of copper before pex be more to protect the pex from heat traveling up the continuous metal in the heater as its generated by the heater itself, rather than the hot water? I can tell you I have touched the pipes a few inches above my heater after its been running and found them to be hot enough to burn skin...much hotter than the water they contain. They cooled rapidly as they rose away from the heater.

 

[Hackney plumbing]

Although I hesitate to re-enter my own thread, I was reading the tangent topic and had a thought. Wouldn't the 18" of copper before pex be more to protect the pex from heat traveling up the continuous metal in the heater as its generated by the heater itself, rather than the hot water? I can tell you I have touched the pipes a few inches above my heater after its been running and found them to be hot enough to burn skin...much hotter than the water they contain. They cooled rapidly as they rose away from the heater.

This just discussion,please dont feel that way. Pex is rated for continuous hot water use at 200 degrees and 80 psi. That will burn skin and burn you quick. The pipes are heating up in that area because of the vent pipe...and thats the reason for the separation. The 18" of separation from a water heater also includes tankless water heaters per code........there is not a ligitimate reason for this....other than thats the way the code was written.

 

[Ballvalve]

A nice 24" copper flex goose neck gives you a free union, a heat trap, and protection from a bad temp switch on any type unit.

Get out your test bench, heat pex to 190' and pressure test. I wouldnt want that "free" pressure relief valve in the house.

BUT - if your flue gas can melt PEX, you need a new water heater, or we are really making garbage.

 

[Hackney plumbing]

A nice 24" copper flex goose neck gives you a free union, a heat trap, and protection from a bad temp switch on any type unit.

Get out your test bench, heat pex to 190' and pressure test. I wouldnt want that "free" pressure relief valve in the house.

BUT - if your flue gas can melt PEX, you need a new water heater, or we are really making garbage.

I dont need to the manufacturers have provided plenty of information and have already done the tests. I posted the temp ratings and pressures. Thats not the failure temps and pressures.......those are working temps and pressures. Failure would likely be at least 25% higher.

For kicks...have any idea why the plumbing code would approve the use of a safety temp/pressure relief valve set at 212???? Wouldn't you think the temp limit would be much less than 212? Thats boiling at atmospheric pressure/sea level.

Why dont they require a temp valve to pop off at around 180.......wouldn't you think that would be safer?

I'll look for your response later,right now I'm going to Walmart and check out their plumbing supplies and maybe buy some ammo...they have cheap prices on ammo. LOL

I enjoy our conversations and mean no disrespect. I hope the feeling is mutual.

 

[Ballvalve]

Watts makes relief valves for 80- 100- 120 just for WH ers. I think the factory rigs should all be at 125 psi.

 

[Hackney plumbing]

Watts makes relief valves for 80- 100- 120 just for WH ers. I think the factory rigs should all be at 125 psi.

Thats pressure,I'm talking about temp. Current standard residential water heaters the relief valve relieves itself at 212 degrees.

 

[MACPLUMB]

Sorry Hackney but you have it wrong again while 212 degrees is the boiling point of water at sea level

by codes " all " temperature and pressure relief valve open at 210 degrees or less they are designed to fail

at 210 or less then per the governing board atsm, aga , etc.

 

[Hackney plumbing]

Sorry Hackney but you have it wrong again while 212 degrees is the boiling point of water at sea level

by codes " all " temperature and pressure relief valve open at 210 degrees or less they are designed to fail

at 210 or less then per the governing board atsm, aga , etc.

I will readily admit when I'm wrong and I made a mistake. Instead of mis-speaking I mis-typed. As far as being wrong "again",please point out any other mistakes you see and quote them for me.


I just reviewed your earlier post on page one of the thread. I suggest you review the thread and all the information I posted from manufacturers AND answer me how pex would be used in a hot water circulating system if your theory that the 18" of copper is to prevent the hot water from melting the pex.

If that were true you couldn't use it for hot water circulation. How much do you think the water would cool off in 18" of copper while its being circulated?

 

[Hackney plumbing]

Here is some info on CPVC connected to a water heater. Both Gas and Electric.

Nibco actually comes out and says why you need seperation. It is nothing to do with hot water melting any type of plastic. Its about the distance from the flue/draft diverter.

.............................................................................................................................................................................................................

Some plumbing codes contain detailed
requirements for connections to gas or electric
storage type water heaters. Determine whether
your code has such requirements and satisfy
them.
If no detailed requirements exist, use the
following information. On electric water heaters
CPVC can be piped directly to the heater with
special metal-to-CPVC transition fittings (photo
L). On high-efficiency, gas water heaters that
use plastic vent piping, CPVC can be connected
directly to the heater just like the electric
water heater connections (photo L). On all other
gas water heaters there should be at least 6
inches of clearance between the exhaust flue
and any CPVC piping (photo K). Twelve-inch
long metal nipples or appliance connectors
should be connected directly to the heater so
that the CPVC tubing cannot be damaged by
the build-up of excessive radiant heat from the
flue.

....................................................................................

Here is the PDF document,there is alot of useful information in it. I suggest everyone read it.

http://www.nibco.com/assets/cpvc_manual.pdf

 

[Jadnashua]

As I said earlier (and Terry posted the UPC code verifying it), the codes (often) do not differentiate the type of WH, and dictate metal for that distance to the WH...the fact that on an electric it may work is irrelevant unless and until the code changes. Your argument about what might work is irrelevant unti and if the code changes to account for the various types of WH that could be installed. Don't particularly care if you like it or not...the goal here is to tell people how to install one and pass code inspection. you can speculate all you want about what might work, but that's not the issue or the point.