# A water heater I did today



## ECH (Jul 27, 2018)

No idea why the pictures are sideways. Maybe a mod could help me out.

First time posting pictures, don't beat me up too bad.


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## Tango (Jan 13, 2018)

You have to rotate your pictures from your computer (right click and rotate) then you can upload them. BUT on this one it didn't seem to work so I opened them with paint rotated them and saved.



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## Tango (Jan 13, 2018)

Why is it on a pedestal? Second question no pan underneath and piped to a floor drain?

And last question what is that jiffy pop tinfoil? Looks like a it's full of popcorn. :wink:


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## OpenSights (Mar 23, 2015)

Tango said:


> Why is it on a pedestal? Second question no pan underneath and piped to a floor drain?
> 
> And last question what is that jiffy pop tinfoil? Looks like a it's full of popcorn. :wink:


It’s on a stand because it’s in a garage. Exhaust from a car could snuff out the pilot.

That vent 90 isn’t code in my area and the foam insulation is a combustible material and can’t be within 6” of the vent. Other than my local codes, looks good.


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## dhal22 (Jul 30, 2010)

Relief valve piped to floor vs outside?


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## OpenSights (Mar 23, 2015)

dhal22 said:


> Relief valve piped to floor vs outside?


Bad idea here. If it develops the drip it could freeze shut.

We just had a code update, if there was no pan and no drain for the pan we no longer need a pan. Apartments, slab and crawl space houses. Basements don’t require pans.


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## Tango (Jan 13, 2018)

OpenSights said:


> Bad idea here. If it develops the drip it could freeze shut.
> 
> We just had a code update, if there was no pan and no drain for the pan we no longer need a pan. Apartments, slab and crawl space houses. Basements don’t require pans.


That would mean he lives in a warm location all year round.

We still need a pan unless it's inches from a floor drain. Yesterday's job I put a capped pan as there weren't any drain and I had them sign a non conformity waiver. It gives them not much of a receptacle but it's better than nothing. It was dripping from the top element.


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## ShtRnsdownhill (Jan 13, 2016)

OpenSights said:


> It’s on a stand because it’s in a garage. Exhaust from a car could snuff out the pilot.
> 
> That vent 90 isn’t code in my area and the foam insulation is a combustible material and can’t be within 6” of the vent. Other than my local codes, looks good.



its on a stand because gasoline fumes are heavier than air, they can collect close to the ground and go boom when the heater kicks on...not so much the exhaust putting the pilot out...:smile:


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## Debo22 (Feb 15, 2015)

ShtRnsdownhill said:


> its on a stand because gasoline fumes are heavier than air, they can collect close to the ground and go boom when the heater kicks on...not so much the exhaust putting the pilot out...:smile:


The standing pilot will make flammable vapors go boom also. That’s why FVIR water heaters were invented. Manufacturer specs say they don’t need to be 18” off the floor anymore due to FVIR but code hasn’t changed yet. 

Garage water heaters don’t require a pan because if the heater leaks it won’t cause damage to the living space. I always install a pan anyway because everyone uses their garage for storage so personal belongings can be damaged.


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## ECH (Jul 27, 2018)

Yup, you guys have worked through all the different things our code calls for already. We are in North Carolina. In garage all piping and expansion tank needs insulation. Direct vents don't get too hot on outer pipe, so our inspectors have pushed us in the direction of bringing the insulation all the way down to the nipples. You can't see in the pic, but I filleted the insulation so it isn't actually touching the vent.

The stands are not required with the FVIR heaters anymore, This is a direct vent anyway, Im not sure they are susceptible to that anyway, but in the interests of not cutting large holes in different places of peoples homes with older heaters using stands, we will be using the stands to use the same penetration through the wall. We just switched from American heaters, which used a flexible vent, to these Rheems, that use a rigid vent. So using the stand and shimming higher or cutting the legs shorting is now going to really be critical to get out the same hole. The rheem vent is 68in from floor to center of vent and not adjustable. Horizontal segment of pipe can extend.

Garage installs do not require a pan, or t and p outside. The silver cover over the exp tank is hvac ducting insulation cut to fit. We do have premade ones that you can get at our shop warehouse, but I forgot one and was an hour away from shop, so I got this at HD and made my own. Straight vertical over the nipple is the only way they will allow the exp tank without support strapping, so in this case thats how I decided to do it since I had the room, and house was on slab. Sometimes I will put the exp tank in crawl, just to clean up the look of the heater install. especially if it is a b-vent.

The only thing I strayed from is that the t and p needs a strap 12in from its termination, and my strap is a little further away, because I only had a 1in two hole strap, and needed to put in over the 90 or the pipe would be loose in the strap. So I put it a bit higher.


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## ECH (Jul 27, 2018)

OpenSights said:


> It’s on a stand because it’s in a garage. Exhaust from a car could snuff out the pilot.
> 
> That vent 90 isn’t code in my area and the foam insulation is a combustible material and can’t be within 6” of the vent. Other than my local codes, looks good.


How do direct vents look in your area?


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## PLUMB TIME (Feb 2, 2009)

ECH said:


> How do direct vents look in your area?



I dont think OS realized it was a direct vent.


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## ECH (Jul 27, 2018)

Understood.


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## hroark2112 (Apr 16, 2011)

Look into the new code upgrades in NC. Can't support the expansion tank by the pipes anymore.


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## Tango (Jan 13, 2018)

Why do you guys have expansion tank for the hot water in a residential house? We don't have them, our systems work fine and I never seen or heard of them until I joined PZ.

What is the reason behind it? It's not like a boiler.


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## OpenSights (Mar 23, 2015)

PLUMB TIME said:


> I dont think OS realized it was a direct vent.


Direct vent, yeah, that wouldn’t fly here though. In this set up it would have to be b vent.


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## OpenSights (Mar 23, 2015)

Tango said:


> Why do you guys have expansion tank for the hot water in a residential house? We don't have them, our systems work fine and I never seen or heard of them until I joined PZ.
> 
> What is the reason behind it? It's not like a boiler.


Expansion tanks aren’t required here. I’ve only seen less than a handful. That being said, we have water towers so we never get insane water pressure. That would be my guess....


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## ShtRnsdownhill (Jan 13, 2016)

OpenSights said:


> Expansion tanks aren’t required here. I’ve only seen less than a handful. That being said, we have water towers so we never get insane water pressure. That would be my guess....


it has more to do with the increase of backflow devices on water mains...the back flow prevents the street main to act like a big expansion tank, so now you have to add one in..if you dont have a back flow device on the main, most likley you wont need an expansion tank on the water heater, but newer codes may call for one regardless...


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## OpenSights (Mar 23, 2015)

ShtRnsdownhill said:


> it has more to do with the increase of backflow devices on water mains...the back flow prevents the street main to act like a big expansion tank, so now you have to add one in..if you dont have a back flow device on the main, most likley you wont need an expansion tank on the water heater, but newer codes may call for one regardless...


I bet that post took a one fingered hour!:vs_laugh:

Interesting! Irrigation, coffee makers, commercial dishwashers, and a few other fixtures require backflow preventers.

Which reminds me... I have to update my lawsuit thread....


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## ShtRnsdownhill (Jan 13, 2016)

OpenSights said:


> I bet that post took a one fingered hour!:vs_laugh:
> 
> Interesting! Irrigation, coffee makers, commercial dishwashers, and a few other fixtures require backflow preventers.
> 
> Which reminds me... I have to update my lawsuit thread....


almost..lol..im getting faster..:laugh:


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## Debo22 (Feb 15, 2015)

ShtRnsdownhill said:


> almost..lol..im getting faster..:laugh:


If you had an iPad you can hit the microphone button and talk to type


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## ShtRnsdownhill (Jan 13, 2016)

that would take all the frustration, oh i mean fun out of it...lol


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## Tango (Jan 13, 2018)

OpenSights said:


> I bet that post took a one fingered hour!:vs_laugh:
> 
> Interesting! Irrigation, coffee makers, commercial dishwashers, and a few other fixtures require backflow preventers.
> 
> Which reminds me... I have to update my lawsuit thread....


It's obvious he's using only one finger, He would need two hands to press the shift key to capitalize each sentence. :glasses:


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## Tango (Jan 13, 2018)

Debo22 said:


> If you had an iPad you can hit the microphone button and talk to type


That would be awesome for a PC(probably exists?), sometimes I don't write posts because of all that hand typing.


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## ShtRnsdownhill (Jan 13, 2016)

Tango said:


> It's obvious he's using only one finger, He would need two hands to press the shift key to capitalize each sentence. :glasses:



the few times i can hit the shift and letter at the same time you get a capital, otherwise grammar dont count during recovery..:vs_laugh:


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## ECH (Jul 27, 2018)

hroark2112 said:


> Look into the new code upgrades in NC. Can't support the expansion tank by the pipes anymore.


I have the newest version, I have not seen anything saying you can't mount vertical. I had a discussion about this with our shop owner, according to him this is the only way they will allow it unstrapped. I guess if it fails, I will know that it doesn't fly. AHJ........



Tango said:


> Why do you guys have expansion tank for the hot water in a residential house? We don't have them, our systems work fine and I never seen or heard of them until I joined PZ.
> 
> What is the reason behind it? It's not like a boiler.


Some localities have water pressures north of 130psi. The PRV won't allow the thermal expansion back to the street, some have a bypass that allows backwards flow if the house gets 10psi above the incoming, but at 130psi, what does that say about how high the house pressure is........

Tankless installs do not require one, but if a recirc line is installed along with the tankless, the exp tank is needed because the check valves make the loop closed.



OpenSights said:


> Direct vent, yeah, that wouldn’t fly here though. In this set up it would have to be b vent.


I'm curious to know why direct vents aren't allowed?


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## ShtRnsdownhill (Jan 13, 2016)

Originally Posted by *OpenSights*  
_Direct vent, yeah, that wouldn’t fly here though. In this set up it would have to be b vent._
I'm curious to know why direct vents aren't allowed? 



your talking apples and oranges....direct vent allowed, but not with that wavy elbow, it needs certain type of vent pipe for positive pressure....


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## ECH (Jul 27, 2018)

hroark2112 said:


> Look into the new code upgrades in NC. Can't support the expansion tank by the pipes anymore.


Here are the sections that talk about exp tanks and PRVs. I know that the spirit of the code is to keep stress off the fittings that the exp tank puts on the pipe and fittings (sideways stress, or pulling stress from hanging upside down). If there is info I haven't seen, I would love to read it.

607.3 Thermal expansion control. Where a storage water
heater is supplied with cold water that passes through a check
valve, pressure reducing valve or backflow preventer, a thermal expansion tank shall be connected to the water heater
cold water supply pipe at a point that is downstream of all
check valves, pressure reducing valves and backflow preventers. Thermal expansion tanks shall be sized in accordance with the tank manufacturer’s instructions and shall be
sized such that the pressure in the water distribution system
shall not exceed that required by Section 604.8.


604.8 Water pressure-reducing valve or regulator. Where
water pressure within a building exceeds 80 psi (552 kPa)
static, an approved water pressure-reducing valve conforming
to ASSE 1003 or CSA B356 with strainer shall be installed to
reduce the pressure in the building water distribution piping to
not greater than 80 psi (552 kPa) static.


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## ECH (Jul 27, 2018)

ShtRnsdownhill said:


> Originally Posted by *OpenSights*
> _Direct vent, yeah, that wouldn’t fly here though. In this set up it would have to be b vent._
> I'm curious to know why direct vents aren't allowed?
> 
> ...



The inner combustion outlet pipe is smooth radius, only the outer, combustion air inlet pipe is corrugated that way. I wonder if that is why it is acceptable?


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## dhal22 (Jul 30, 2010)

OpenSights said:


> Direct vent, yeah, that wouldn’t fly here though. In this set up it would have to be b vent.


That heater is a direct vent design.


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## skoronesa (Oct 27, 2015)

Tango said:


> Why do you guys have expansion tank for the hot water in a residential house? We don't have them, our systems work fine and I never seen or heard of them until I joined PZ.
> 
> What is the reason behind it? It's not like a boiler.





If you have a well and no check valve between well tank and the rest of the house than the well tank will accept any expansion in the system. If you are on city water than you don't normally have room in the plumbing for the expansion that can occur when the water is heated which can lead to high pressures. Also, in some oddball cases you might have a check valve before the water heater in which case you would need an expansion tank on the hot side. Some places require them on one side or the other with the thinking being that one of the two nipples could get plugged shut with minerals. Some places require them on the hot side because there is a flow check on the cold side of many heaters which could act as a pressure check valve.


Personally, the only firm scenario for an expansion tank is when you have city water, but I don't think it matters too much which side of the heater you put it on. Around here they are extremely rare in any circumstance.

Also, I call them HOT water heaters, Ya wanna fight about it?




.


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## Tango (Jan 13, 2018)

skoronesa said:


> If you have a well and no check valve between well tank and the rest of the house than the well tank will accept any expansion in the system. If you are on city water than you don't normally have room in the plumbing for the expansion that can occur when the water is heated which can lead to high pressures. Also, in some oddball cases you might have a check valve before the water heater in which case you would need an expansion tank on the hot side. Some places require them on one side or the other with the thinking being that one of the two nipples could get plugged shut with minerals. Some places require them on the hot side because there is a flow check on the cold side of many heaters which could act as a pressure check valve.
> 
> 
> Personally, the only firm scenario for an expansion tank is when you have city water, but I don't think it matters too much which side of the heater you put it on. Around here they are extremely rare in any circumstance.
> ...


Wouldn't the T/P on the water heater serve that purpose if there is too much pressure?


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## skoronesa (Oct 27, 2015)

Tango said:


> Wouldn't the T/P on the water heater serve that purpose if there is too much pressure?





Well ideally the expansion tank would absorb the pressure fluctuations reducing the fatigue on the system specifically the joints. The t&p would only limit the ultimate pressure but would not stop these fluctuations. 



Expansion and contraction causes metal fatigue and more leaks than corrosion/erosion. That's why valves which are never used develop leaks at the packing nut. The contraction squishes the packing and the expansion makes a gap again.



Also, we all know how rarely t&p valves blow off and when they do they never shut correctly. Theoretically an expansion tank could stop this.


On the few occasions I have installed an expansion tank I always install them air up so even if they get a hole in the bladder they still retain most of the air and hopefully catch any air that comes through the piping as well. I always strap my tanks/pipes. Not supporting a tank is just stupid, that's just 30lbs of stress constantly pushing on the pipes.




.


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## hroark2112 (Apr 16, 2011)

ECH said:


> Here are the sections that talk about exp tanks and PRVs. I know that the spirit of the code is to keep stress off the fittings that the exp tank puts on the pipe and fittings (sideways stress, or pulling stress from hanging upside down). If there is info I haven't seen, I would love to read it.
> 
> 607.3 Thermal expansion control. Where a storage water
> heater is supplied with cold water that passes through a check
> ...



This is the changes to the code. Expansion tanks are no longer allowed to be supported by the piping.


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## GAN (Jul 10, 2012)

Tango said:


> Why do you guys have expansion tank for the hot water in a residential house? We don't have them, our systems work fine and I never seen or heard of them until I joined PZ.
> 
> What is the reason behind it? It's not like a boiler.



All codes should required expansion tanks on "closed systems" Any check valve that stops the natural expansion back into the water main (we have a lot of them on meter yokes & some cases whole system RPZ's) can cause reliefs to spit, or ball cocks to blow, relieve pressure then do it again.

Illinois also requires metallic piping for relief valve drains.


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## skoronesa (Oct 27, 2015)

GAN said:


> All codes should required expansion tanks on "closed systems" Any check valve that stops the natural expansion back into the water main (we have a lot of them on meter yokes & some cases whole system RPZ's) can cause reliefs to spit, or ball cocks to blow, relieve pressure then do it again.
> 
> Illinois also requires metallic piping for relief valve drains.





Every time I see pvc on a relief valve, especially when it isn't a straight shot, all I can picture is it melting into spaghetti and the joints coming apart.






.


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## 89plumbum (May 14, 2011)

hroark2112 said:


> This is the changes to the code. Expansion tanks are no longer allowed to be supported by the piping.


...


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## ECH (Jul 27, 2018)

Thank you for the clarification. I will have to fix that if it fails. My saving grace this time is that my shops owner has mentioned that doing it vertically like that is acceptable. time will tell.

Just out of curiosity, where are you finding that verbiage in the code?

Im looking right at my 2018 pdf, and in chapter 3, 308 "piping support" I have this:

SECTION 308
PIPING SUPPORT
308.1 General. Plumbing piping shall be supported in accordance with this section.
308.2 Piping seismic supports. Where earthquake loads are
applicable in accordance with the building code, plumbing
piping supports shall be designed and installed for the seismic
forces in accordance with the International Building Code.
308.3 Materials. Hangers, anchors and supports shall support
the piping and the contents of the piping. Hangers and strapping material shall be of approved material that will not promote galvanic action.
308.4 Structural attachment. Hangers and anchors shall be
attached to the building construction in an approved manner.
308.5 Interval of support. Pipe shall be supported in accordance with Table 308.5.


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## OpenSights (Mar 23, 2015)

Just clarifying...


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## GAN (Jul 10, 2012)

The caveat is the "manufactures installation guide"

For instance (sorry from Lowes). >>> http://pdf.lowes.com/installationguides/091194008415_install.pdf 

"The expansion tank is designed to be supported by the system piping in the "vertical" position. If, however, the expansion tank must be installed horizontally, as shown in figure 2, it must be supported by adequate strapping (not supplied).

I would have no issue vertically on top of a tee or hanging vertically of a horizontal line. Since it is specifically listed as an approved method via the manufacture.

I think you will find most tank manufactures have similar guides.


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## MACPLUMB777 (Jun 18, 2008)

Tango said:


> Wouldn't the T/P on the water heater serve that purpose if there is too much pressure?


NO ! Per code in States :biggrin:

#1 Continually open and closing of the valve weakens the spring where it will not hold the 150 psi regard by code,
#2 Continually weeping of valve causes lime/calcium build up which can 
block the valve OR cause it to freeze close preventing it from operating 
when needed !
#3 Think of a P&T valve as a Emergency brake like on your truck it doe's
not operate except in a Emergency like if the thermostat malfunctions
causing the heater to over heat causing a Explosive situation ! ! :vs_OMG:


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## skoronesa (Oct 27, 2015)

Like, almost all of the expansion tanks we install have the 3/8" square nut welded to the top so you can hang the tank on some 3/8" rod in the appropriate vertical position where it is most likely to retain air.

Rather comically, many of the steel well tanks also have the nut welded to the top. I always chuckle at the idea of 25gallons hanging from the ceiling. Obviously it's just to stop the tank from tipping over.


.


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## ECH (Jul 27, 2018)

GAN said:


> The caveat is the "manufactures installation guide"
> 
> For instance (sorry from Lowes). >>> http://pdf.lowes.com/installationguides/091194008415_install.pdf
> 
> ...


We see a lot of them mounted hanging off the pipe. It gets hairy when somebody lets one hang on pex and it is waterlogged. And sometimes even on copper, the sideways stress on the joints just looks like a terrible idea. Thus, my install of the tank straight above the nipple, all force driving downward straight.

The manufactures recommend having 18in of piping between the heater, and the exp tank. I assume to keep the heated water away from the bladder. Although I have installed them on recirc lines (per code where we are) where thermal expansion occurs.

I always put them on the cold side of water heaters for that reason. 
@Tango, the water pressure fluctuates greatly during the day/night where we are. Based on demand I suppose. The PRV and expansion tank work together to control the thermal expansion, like others have mentioned.

Once the prv fails, the exp tank is not far behind. Then the next thing you know, customers are calling us for a "water leak from that pipe at the water heater."

So now it's $350 for the prv, $240 for the expansion tank, and $220 for the T and P valve.

But now that I see that your heater is 10yrs old, do you really want to sink that money into it when you "might" get two more years out of it with our garbage water quality?

An ounce of prevention........


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## hroark2112 (Apr 16, 2011)

This is how I do mine now. PEX drop ear elbow held to the structure by 3 wood screws.


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## GAN (Jul 10, 2012)

Always mount on the cold side period.

In hroark2112 picture. Can't really focus. I don't really like the idea of a valve between the on demand heater and expansion tank. Common though I believe.


Great way to mount it dealing with PEX though.


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## ECH (Jul 27, 2018)

We use the drop ears a lot in our shop. I agree with the others about mounting with air side of the bladder up, so the air stays up, and also so the weight of the water isn't adding to the strain on the bladder. Maybe not neccessary, but I do that when I can.

As far as always being on the cold side, I disagree. I did a tankless install on a monster house, that had a 50 gal electric heater that acted as a storage and heating tank just for the circulation pump/loop, that was on all the time. The tankless fired up when there was demand for hot water and the way it was piped, the tankless fed most of the house because it was the path of least resistance. There was a check valve on the hot outlet of the tankless before it teed into the circ loop.

In this instance, the thermal expansion cannot escape back into the cold line because of the check valve, and the expansion tank is needed on a hot pipe. Not that there is going to be a ton of thermal expansion, but theoretically, it needed to be there.


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## Toli (Nov 7, 2015)

Amtrol says to mount theirs on the cold supply in the downward position. I take that to mean the connection on top. 

They also say to make sure the piping can support the weight of the tank, so......


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## hroark2112 (Apr 16, 2011)

GAN said:


> Always mount on the cold side period.
> 
> In hroark2112 picture. Can't really focus. I don't really like the idea of a valve between the on demand heater and expansion tank. Common though I believe.
> 
> ...



The only valve between the heater and the expansion tank is the valve on the service kit. I can't figure out how to get between that valve and the heater though :vs_laugh:


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