Opinion on expansion tank installation. Picture included.

[jadnashua]

If the heating elements ever failed to be controlled properly, the temperature could (I think, anyway) exceed the safe operating temperature of the cpvc before the safety circuits shut it off or the T&P valve opened. Personally, I would not have cpvc connected directly to the WH, regardless of the type.

[Redwood]

I believe the ECO trips at 200 and CPVC Flowguard gold is rated at 100 psi @ 200 degrees...

It's still junk and when I work in it I transition to PEX with a sharkbite and thats all folks...

But Florida Code does allow the direct connection to the water heater...

[John Vega]

The Plumbing Code is a minimum standard.

I was being sarcastic :-)

[ballvalve]

I found the BIBLE on water heater installs from Watts. Its fun arguing, but if this was made into a sticky, we would all benefit. Great graphics and advice with calcs for tanks and valves.... have a look

http://www.blueridgecompany.com/docu...mExpansion.pdf

Take a good look at the 'inline expansion tanks' - interesting, made like hydraulic acculumulators that last forever.

[master plumber mark]

you need to get them to at least strap the expansion tank to the wall with
metal strapping to hold the weight.... possibly a 2x4 stilt under the cpve for support
on the pipe too......eventually it will get water logged and weigh about 35 lbs....



I feel that the better thing to do is simply take it out and put a plug in that fitting
expansion tanks are pretty much a joke and cause more troubles than they remedy
no one ever installs them properly with support and never inspects them years from now..





here is a real beauty I had to cut out and re-do one evening in February.. stupid DIY installation with shark plastic shark bite couplings to the heater that finally snapped and flooded the basement.. the expansion tank probably weighed 50 lbs and dropped like a lead weight to the floor,

[Redwood]

here is a real beauty I had to cut out and re-do one evening in February.. stupid DIY installation with plastic shark bite couplings to the heater that finally snapped and flooded the basement.. the expansion tank probably weighed 50 lbs and dropped like a lead weight to the floor,

Oh you mean John Guest fittings.... Big difference from a SharkBite

[master plumber mark]

Wow Redwood....
I learnt something new today...

so those are john guest fittings....

they dont leak but look like pretty much junk..

except for being plastic, their is really no difference
between them....

and they should never be used to be part of the support for a therm tank..



I wonder how much cheaper they are over a shark bite??
probably half the price??....

[Gary Swart]

So Plumber Mark, since expansion tanks are just a joke, I should remove mine and just let the T/P spew water each time the water heater operates? Guess the two steel straps from two joists that support the tank are not going to hold the tank if/when it fails and water logs? When (not if) my tank fails, I will know even if I don't inspect it daily. The T/P will trip. Fortunately, my T/P pipe ends at a floor drain so I won't have a flood if I don't see the problem for awhile.

[hj]

When a pipe is filled with water, having it in proximity to a heat source will SELDOM cause it to fail. Have you never boiled water in a paper cup over a campfire? ALL water heaters can output overheated water in the event of a malfunction, which can AND WILL backup into the cold water inlet, and THAT is the reason for the copper requirement. You probably DO NOT want to have the expansion tank removed because, in your situation it may be fulfilling a need, but it should be secured properly. The problem with the plumber being the one that does the housing subdivision is that he ONLY has to know what they do every day, NOT the reason for it or sometimes the proper way.

[master plumber mark]

So Plumber Mark, since expansion tanks are just a joke, I should remove mine and just let the T/P spew water each time the water heater operates? Guess the two steel straps from two joists that support the tank are not going to hold the tank if/when it fails and water logs? When (not if) my tank fails, I will know even if I don't inspect it daily. The T/P will trip. Fortunately, my T/P pipe ends at a floor drain so I won't have a flood if I don't see the problem for awhile.

A quick question for you...Gary
did they install a pan..under the new heater?? YES> or NO???
so in case it ever ruptures and floods the entire home
before you have a chance to see it leaking...???

(please take not e of my new avatar)

we always like to install the heater in a PAN...

we always try to run the pan and the t+p drain
off the pressure relief to the nearest drain....or combine them

A water heater pan IS VERY WISE,
this keeps me from being blamed for floods years from now
and a water heater pan is a much better choice over the thermal tank
if you have a real floor drain near by,,.....



YES....On occasion the t+p might weep.... depending on the pressure in your home
and wether you have a prv valve ....... Most times they are piped into a dedicated
drain and its never a huge issue in the first place......

if they weep ......its usually once in a baby blue moon,....... if it is going into a DRAIN..
the odds are you will never even notice an ocassional drip ... "weep" from the pipe.


If the weeping becomes a problem, simply change the T+P valve and see if
it remedies itself.... we have done this on occasion for folks that dont want to
cough up the money for a thermal tank..



also...if you dont have a floor drain near by,
we have run the pipes off the t+p to the
laundry drain pipes

we have actually poked pipes
out the side of the homes before to discharge the drain pans
when they were on slab homes. when no drains were available................




Now, if the expansion tank breaks off the 3/4 cpvc pipe when
it gets heavy and water logged years from now ....
there will certainly be a huge , massive......flood.. spraying everywhwere.

please weigh your options yourself....
and you do whatever you think is best

I dont really want to get into a huge
debate about this .....especially with a bunch of people
that dont do this for a living..
and dont know what they are talking about.

...

[hj]

quote; or combine them

SELDOM, if ever, a good idea, unless they are joined RIGHT AT the drain outlet. Otherwise the T&P WILL backflow into the pan and overflow it. And as for "But Florida Code does allow the direct connection to the water heater... ", that is a good example of a code that is a minimum standard rather than a professional way to do it.

[SteveW]

MPM says:
"did they install a pan..under the new heater?? YES> or NO???
so in case it ever ruptures and floods the entire home
before you have a chance to see it leaking...???"
**********************************************

I'm not a pro, but --

looking at the Watts site mentioned above, it seems to suggest that a thermal expansion tank might actually PREVENT a WH from rupturing - this seems plausible to me that if a home has thermal expansion problems that are not corrected, it could certainly stress the WH tank (that extra 1/2 gallon of "expanded" water has to go SOMEWHERE) and cause cracks in the lining, etc.

So - under certain circumstances, it appears that having some sort of thermal expansion relief (expansion tank or other mechanical device like the Watts pressure-relief ballcock, etc.) could potentially make it less likely for a WH to rupture.

Do you pros buy this? Again, from a homeowner's perspective it seems reasonable to me. I have observed in my own home that my water softener (a dreaded Kenmore) has functioned much better with longer intervals to replace rotors since I have put in an expansion tank, so it seems to me that other pressure-sensitive parts of the plumbing system could have longer lifespans with proper relief of thermal expansion issues.

[master plumber mark]

quote; or combine them

SELDOM, if ever, a good idea, unless they are joined RIGHT AT the drain outlet. Otherwise the T&P WILL backflow into the pan and overflow it. And as for "But Florida Code does allow the direct connection to the water heater... ", that is a good example of a code that is a minimum standard rather than a professional way to do it.

normally we install the heater on bricks
in the pan....

we usually will run the t+p valve down into the pan ,
then run the pan drain over to the floor drain... or run the t+p
over to the drain, depending on the situation.

but I have made that mistake before......

[master plumber mark]

MPM says:
"did they install a pan..under the new heater?? YES> or NO???
so in case it ever ruptures and floods the entire home
before you have a chance to see it leaking...???"
**********************************************

I'm not a pro, but --

looking at the Watts site mentioned above, it seems to suggest that a thermal expansion tank might actually PREVENT a WH from rupturing - this seems plausible to me that if a home has thermal expansion problems that are not corrected, it could certainly stress the WH tank (that extra 1/2 gallon of "expanded" water has to go SOMEWHERE) and cause cracks in the lining, etc.

So - under certain circumstances, it appears that having some sort of thermal expansion relief (expansion tank or other mechanical device like the Watts pressure-relief ballcock, etc.) could potentially make it less likely for a WH to rupture.

Do you pros buy this? Again, from a homeowner's perspective it seems reasonable to me. I have observed in my own home that my water softener (a dreaded Kenmore) has functioned much better with longer intervals to replace rotors since I have put in an expansion tank, so it seems to me that other pressure-sensitive parts of the plumbing system could have longer lifespans with proper relief of thermal expansion issues.

Watts sells expansion tanks for a profit and a living and have a vested interest in telling the public that you cant live without them....... but yes you can....

Their are literally a hundred million homes without them in this country that have worked perfectly fine for decades and decades... and now all of a sudden the world is going to come to an end if one is not installed on your system..

In this city alone their are literally tens of thousands of water heaters installed on the second floors of the homes without thermal expansion tanks.... all built around 1995..and after to this date..

those plumbers ignored the thermal tanks but did install alluminum pans and piped the pan and the t+p line to the flooor drains in the room... they have mostly all worked fine till the heaters started leaking.....


if you have dramatically high pressure you should consider one,, and also a PRV valve to kick it down to 70psi...



Sometimes I have wondered which congressmen watts had to bribe to make thermal expansion tanks code...

If you are not willing to service the system yourself, its just a matter of time
before that Expansion tank becomes a liability when it gets waterlogged....

also, those Watts pressure releif ballcocks scare the dickens
out of me and I wont trust them...



this is what a water heater looks like after 10 years of service in Indiana
with no one ever flushing it out.....
http://www.youtube.com/v/mjWDyaQGDiY...ram%3E%3Cparam

[SteveW]

Yikes - that's a nasty collection of hard-water minerals! I never thought about it before this, but I guess that the heat from the WH does something to the calcium and magnesium in the water to make them settle out?

Going back to the point that residential plumbing systems have survived without expansion tanks for many years - yes, true - my parents house never had on one and didn't seem to need it. The two houses I've owned have both had thermal expansion problems, though. Are PRVs being used more than they used to? Or are PRVs now made with check valves, and they didn't used to be?

Sounds like something has changed.