Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Plumbing

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 01-04-2013, 11:48 AM   #16
Member
 
Join Date: Apr 2011
Location: North Carolina, USA
Posts: 3,007
Rewards Points: 2,214
Default

Replacing water heater


Quote:
Originally Posted by AllanJ View Post
I don't think the lack of an expansion tank shortens the life of a water heater but when the tank has nearly rusted out in a spot, the added pressure given the lack of an expansion tank can be the straw that breaks the camel's back a tad sooner.
In other words, lack of an expansion tank can shorten the life of the water heater

You can't predict where something will fail. It's not just the tank, it's the connections. It's not just the water heater, it's the entire system.

Think of it as cheap insurance. Maybe a pipe seal just outside the range of the drip pan of the water heater will start to leak. This could easily go unnoticed, and could easily cost tens of thousands of dollars in repairs if it causes water damage for a few months behind your walls or under your floors. This is true of any plumbing leak in your whole system.

Leaks are less likely with an expansion tank than without one. Exactly how much less likely? No one can tell you, but it's enough that it's a pretty good insurance bet.

jeffnc is offline   Reply With Quote
Old 01-04-2013, 11:52 AM   #17
Member
 
Join Date: Apr 2011
Location: North Carolina, USA
Posts: 3,007
Rewards Points: 2,214
Default

Replacing water heater


Quote:
Originally Posted by jagans View Post
Assuming he has city water, which he does not say,

Why is an expansion tank needed prior to a HWH? And why would the lack of one cause premature failure of a tank type water heater?
Technically the expansion tank can go anywhere in your plumbing supply system (key word being "your" - meaning on your side of the city's incoming valve.)

The expansion tank helps control the buildup of pressure caused by your water heater heating your water (water expands as it heats up). The pressure is increased everywhere in your system, not just in the hot water heater. Technically it can cause premature failure anywhere in your plumbing. (Although if the pressure rises above what your plumbing components are rated at, then you could hardly call it "premature").
jeffnc is offline   Reply With Quote
Old 01-04-2013, 11:52 AM   #18
moderator
 
TheEplumber's Avatar
 
Join Date: Jul 2010
Location: North Idaho
Posts: 7,012
Rewards Points: 2,212
Default

Replacing water heater


Quote:
Originally Posted by jeffnc View Post
In other words, lack of an expansion tank can shorten the life of the water heater

You can't predict where something will fail. It's not just the tank, it's the connections. It's not just the water heater, it's the entire system.

Think of it as cheap insurance. Maybe a pipe seal just outside the range of the drip pan of the water heater will start to leak. This could easily go unnoticed, and could easily cost tens of thousands of dollars in repairs if it causes water damage for a few months behind your walls or under your floors. This is true of any plumbing leak in your whole system.

Leaks are less likely with an expansion tank than without one. Exactly how much less likely? No one can tell you, but it's enough that it's a pretty good insurance bet.
Exp tanks are fine until they get water logged........then its worthless insurance
I don't have one, never had one. My extra pressure goes back to the city. In my case an unnecessary expense
__________________
When posting in forums, letting us know your location will help others give better feedback/advice/solutions to your questions
TheEplumber is offline   Reply With Quote
Old 01-04-2013, 11:56 AM   #19
Member
 
Join Date: Apr 2011
Location: North Carolina, USA
Posts: 3,007
Rewards Points: 2,214
Default

Replacing water heater


Quote:
Originally Posted by TheEplumber View Post
Exp tanks are fine until they get water logged.......
Please explain. Expansion tank malfunction or filled to capacity? What you are saying it's like saying "shocks on your car are fine, until they break." Because that's not a reason to stop using shocks.

Quote:
Originally Posted by TheEplumber View Post
My extra pressure goes back to the city. In my case an unnecessary expense
What city?

Last edited by jeffnc; 01-04-2013 at 12:00 PM.
jeffnc is offline   Reply With Quote
Old 01-04-2013, 12:13 PM   #20
moderator
 
TheEplumber's Avatar
 
Join Date: Jul 2010
Location: North Idaho
Posts: 7,012
Rewards Points: 2,212
Default

Replacing water heater


Quote:
Originally Posted by jeffnc View Post
Please explain. Expansion tank malfunction or filled to capacity? What you are saying it's like saying "shocks on your car are fine, until they break." Because that's not a reason to stop using shocks.



What city?
I'm saying that exp. tanks do fail, whether it's on a well or a water heater. The pressure needs to be calibrated when installed to match house pressure(don't trust factory settings) and checked periodically- when flushing water heater.
I have no check valves, pressure regs, or backflow devices on my main. All the excess pressure feeds back to the city main. But it is becoming more common to find check valves on supply lines though, in which case a exp tank is needed.
__________________
When posting in forums, letting us know your location will help others give better feedback/advice/solutions to your questions
TheEplumber is offline   Reply With Quote
Old 01-04-2013, 12:22 PM   #21
Member
 
Join Date: Apr 2011
Location: North Carolina, USA
Posts: 3,007
Rewards Points: 2,214
Default

Replacing water heater


Quote:
Originally Posted by TheEplumber View Post
I'm saying that exp. tanks do fail, whether it's on a well or a water heater.
Of course, everything can fail, doesn't mean we don't install anything.


Quote:
Originally Posted by TheEplumber View Post
The pressure needs to be calibrated when installed to match house pressure(don't trust factory settings)
Yes, of course, they don't ask you to trust the factory settings, they instruct you to set the pressure. Anyone with a bike pump, tire pressure gauge, and a phone to call the city water service to check their pressure can do it.

Quote:
Originally Posted by TheEplumber View Post
I have no check valves, pressure regs, or backflow devices on my main. All the excess pressure feeds back to the city main.
I guess you're not going to tell us which city, but I was curious. I thought almost anything big enough to be called a city had check valves installed.
jeffnc is offline   Reply With Quote
Old 01-04-2013, 12:24 PM   #22
Member
 
Join Date: Apr 2011
Location: North Carolina, USA
Posts: 3,007
Rewards Points: 2,214
Default

Replacing water heater


By the way, a note about setting your expansion tank pressure.

I recommend calling the city to check rather than, or at least in addition to, checking the plumbing pressure yourself. This is because cities try to maintain a certain pressure or range. If you catch them at a "bad time", you could end up setting your expansion tank wrong. For example, my local service tries to maintain 60 psi, but admits it's really a range starting at 40 psi. If I measure it one day at 40, or if it's temporarily dropped even lower, I'll set it wrong, because the expansion tank should really be set at 60.
jeffnc is offline   Reply With Quote
Old 01-04-2013, 12:25 PM   #23
Newbie
 
Join Date: Jan 2013
Posts: 8
Rewards Points: 10
Default

Replacing water heater


You reaaly only need an expansion tank if you have a check valve on your plumbing system. He is correct about the pressure going back into the city side. the only way it wouldn't would be a check valve. Now some city's have the new water meters with built in check valves. So if you have no check valve, I wouldn't worry about it. If they make you pull a permit then you are SOL. City will make you add one. That's life and it STINKS!!!!
fasteddie3 is offline   Reply With Quote
Old 01-04-2013, 12:27 PM   #24
Member
 
Join Date: Sep 2012
Location: Central Florida
Posts: 146
Rewards Points: 75
Default

Replacing water heater


Since I'm on a private well with a 40/60 pressure switch, what would I set my expansion tank pressure to? Finally, since you're saying an expansion tank can be installed anywhere in the plumbing system (on your side), wouldn't the well pressure tank double has an expansion tank therefore not requiring the use of an expansion tank?
BrandonD is offline   Reply With Quote
Old 01-04-2013, 12:35 PM   #25
moderator
 
TheEplumber's Avatar
 
Join Date: Jul 2010
Location: North Idaho
Posts: 7,012
Rewards Points: 2,212
Default

Replacing water heater


Quote:
Originally Posted by jeffnc View Post
Of course, everything can fail, doesn't mean we don't install anything.




Yes, of course, they don't ask you to trust the factory settings, they instruct you to set the pressure. Anyone with a bike pump, tire pressure gauge, and a phone to call the city water service to check their pressure can do it.



I guess you're not going to tell us which city, but I was curious. I thought almost anything big enough to be called a city had check valves installed.
You're making the assumption that all posters here are intelligent.
The city does not matter- its the age of their system and the depth of their pocket books to upgrade. I'm sure you wont find the latest and greatest pipe material used in cities either.
__________________
When posting in forums, letting us know your location will help others give better feedback/advice/solutions to your questions
TheEplumber is offline   Reply With Quote
Old 01-04-2013, 12:37 PM   #26
Member
 
Join Date: Apr 2011
Location: North Carolina, USA
Posts: 3,007
Rewards Points: 2,214
Default

Replacing water heater


If your well tank has a bladder and there is no sort of check valve between your house plumbing and the well tank, then the well pressure tank should work.

I recently flipped a house that had a well tank and an expansion tank on the water heater. I never did try to figure out why it had both - it might have been needed, or it might not have.

Anyway, if you use an expansion with your well pressure set to 40-60, I'd set the expansion tank at 60.
jeffnc is offline   Reply With Quote
Old 01-04-2013, 12:39 PM   #27
Newbie
 
Join Date: Jan 2013
Posts: 8
Rewards Points: 10
Default

Replacing water heater


Quote:
Originally Posted by BrandonD View Post
Since I'm on a private well with a 40/60 pressure switch, what would I set my expansion tank pressure to? Finally, since you're saying an expansion tank can be installed anywhere in the plumbing system (on your side), wouldn't the well pressure tank double has an expansion tank therefore not requiring the use of an expansion tank?
It has to be installed between the shut off valve to the water heater and the cold inlet side of the water heater. That's the proper installation. That prevents the tank of always being protected. What's the point of putting it in and having someone shut the water off to tank but still on. It would be building pressure and no protection from expension tank.
fasteddie3 is offline   Reply With Quote
Old 01-04-2013, 12:39 PM   #28
Member
 
Join Date: Apr 2011
Location: North Carolina, USA
Posts: 3,007
Rewards Points: 2,214
Default

Replacing water heater


Quote:
Originally Posted by TheEplumber View Post
I'm sure you wont find the latest and greatest pipe material used in cities either.
The check valve is related to potentially serious public health issues, so they usually upgrade that sooner rather than later.
jeffnc is offline   Reply With Quote
Old 01-04-2013, 12:49 PM   #29
moderator
 
TheEplumber's Avatar
 
Join Date: Jul 2010
Location: North Idaho
Posts: 7,012
Rewards Points: 2,212
Default

Replacing water heater


Quote:
Originally Posted by fasteddie3 View Post
It has to be installed between the shut off valve to the water heater and the cold inlet side of the water heater. That's the proper installation. That prevents the tank of always being protected. What's the point of putting it in and having someone shut the water off to tank but still on. It would be building pressure and no protection from expension tank.
I recently put a heater in on a commercial job. All work to be installed as detailed on the prints.
Water heater had valves on CW supply and HW out. That's typical for commercial. I then through the drawings down and put the exp. tank on the heater(between CW valve and tank). Engineer comes back and tells me to move it to the hot side per drawing detail. I didn't argue- just wanted off that job
__________________
When posting in forums, letting us know your location will help others give better feedback/advice/solutions to your questions
TheEplumber is offline   Reply With Quote
Old 01-04-2013, 12:50 PM   #30
Member
 
Join Date: Apr 2011
Location: North Carolina, USA
Posts: 3,007
Rewards Points: 2,214
Default

Replacing water heater


Quote:
Originally Posted by fasteddie3 View Post
It has to be installed between the shut off valve to the water heater and the cold inlet side of the water heater. That's the proper installation. That prevents the tank of always being protected. What's the point of putting it in and having someone shut the water off to tank but still on. It would be building pressure and no protection from expension tank.
You kind of have a point, but it would be a pretty unlikely scenario. There's no problem with the water heater just being "on" because water doesn't expand if it's already hot. The only problem would be if the water heater were drained of hot water first. So you'd have to take a long shower, then immediately go to your water heater and turn off the cold water supply, then go back and put your clothes on, and then do whatever plumbing you had to do right after taking a shower And the real question is, why would you need to turn off the water supply to the hot water heater unless you were doing some serious work to it or replacing it? And if you were doing that, why on earth would you not turn off the breaker to it? I'd worry more about working on a hot water heater without the breaker off than I would about a increase in pressure over 30 minutes.

jeffnc is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Question on return line for water heater daluu Plumbing 10 09-09-2012 10:38 PM
Water heater issues?!? NJdan Plumbing 0 08-30-2012 08:22 AM
elevate electric water heater? crankbait09 Plumbing 18 04-18-2011 11:35 AM
Pressure drop across water heater, low hot water flow HVAC_NW Plumbing 2 01-17-2011 10:43 PM
Solar hot water indatom123 Green Home Improvement 0 12-19-2010 12:01 AM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.