Water Heaters - Expansion Tanks

Can I attach this tank to the supply line with a flexible pipe--copper or Stanless steel, the same ones used to attach the water heater to the water lines?

You can do anything you want. The better question might have been: Tim, how would you do it in your home? The tank would screw onto a male nipple soldered to hard copper. The nipple would point up to the sky so the water moving into the tank would always push the bladder up and gravity would always be trying to pull the water down.

I had to replace a leaking expansion tank. I turned off the water flow, unscrewed the old tank, screwed in the new tank, and turned back on the water flow. Did I miss something?

No. Unless you installed the wrong-sized tank.

What pressure do I charge my expansion tank to when filling the closed loop system?

Whatever the enclosed written instructions say.

I'm in the process of buying a home. The failed the hot water heater for not having an expansion tank. Is this something that can be added to an existing hot water heater? How much does this typical cost?

Maggie,
They can be added with no problems. It is impossible for me to give you an accurate quote. Besides..... the *seller* should be paying!

I assume if you have a supply pressure via a well with say a 30/50 switch (the pressure varies accordingly) that you use the setup pressure of your water storage tank (i.e. just below the low pressure switch setting?

50 gal gas hwh. 4 yrs old put in when we built the house. grundfos recrecirculating pump installed on hot water side. plumbeer put exspasion tank on hot water side above the tank. is this right? now the problem, only 2 people in house and can't take back to back showers without running out of hot water. 80psi fron street to prv down to 60 psi 2nd plumber last week installed a spring loaded ckeck valve after the prv. now i still don't have enough hot water and now water coming out of the pop off valve when the heater is filling or heating back up. what's the promblem.

Darrell,
You need to check with the expansion tank manufacturer on its specific placement. It sounds like your dip tube might have failed.

I hear a loud whistling sound only when someone uses water in the house. I do NOT have an expansion tank on the water heater. Can you explain what the problem might be ?

Robert,
Vibration that is happening in a pipe or valve body. It is caused by the moving water.

When my well failed I decided to hook into the city water. I just noticed that my pressure relief valve has been going off sending out large quantities of water. I suspect it's only after back to back showers. Should I try addng an expansion tank first, or should I replace the valve or should I replace the electric heater all in one go? The heater is almost ten years old.

Sean,
That is a tough call. I have seen some water heaters last 15-20 years! The expansion tank should solve the blowout issues. I explain in a sister column to this one why the water is blowing past the T/P valve.

HiYa!

We installed a new toilet a few months ago that doesn't have the "ball-float" system, it's an American Standard Champion 4 system. Since then, our water heater blows water from the pop-off valve. It's a unique house and the drain in the basement only runs with a sump- pump. If we get an expansion tank, will this resolve our issue? I tried turning down the temp, and it doesn't overflow. But, it's lukewarm... I think that the water used to release pressure through the lines to the toilet tank before we installed the new one. I really appreciate your help. Thanks!

Jackie,
An expansion tank will likely solve the problem. The old toilet valve might have been the pressure-release point. As the water heater worked, it pushed cold water past that valve. The new valve must be stronger and then the weak link became the T/P valve. Just a hypothesis.....

My house has two 40 gallon hot water heaters that are connected serially (the hot water output of the first one feeds the cold water input of the second one). My assumption is that this should be treated as an 80 gallon system and that I should put a single expansion tank (rated for 80 gallons) on the cold water input pipe leading to the first hot water heater. However, my neighbor also has two 40 gallon hot water heaters connected serially and in his house there is one expansion tank (50 gallon capacity) on the cold water line leading to the system and one expansion tank (50 gallon capacity) in between the two hot water heaters. Which is the correct installation method and why?

Mike,
Treat it as an 80-gallon installation. Why? Because you heated 80 gallons of water. Your neighbor has sufficient tank capacity. Read the instructions to see where they say they should be installed.

Is there any code mandating that the expansion tank be laterally connected, or supported otherwise?

Fred,
There may be. I tend to follow the written instructions that are produced by the manufacturer.

i have a problem with hot water coming out of the cold water faucets throughout my house. It happens throughout the day at any time. we need to run the cold water for about 2 minutes to get cold. it is even coming out of the chilled water dispenser of the refrigerator at a warm temperature.
we have a oil fired boiler with a tankless water heater...(i believe that is what it is called)...and this system is approx 5 years old. these symptoms just started about 2 days ago.
do you have any ideas?

Mark,
I have to admit, this is the first time in my life I have heard of this exact problem. There have been plenty of times before, but there was always a change to the system that was the root of the problem. The way you make it sound, this started on its own.

I know how to stop it..... but that doesn't say why it happened.... You can put a check valve on the cold water inlet pipe that feeds the water heater.

Can you install an expansion tank on the hot side of a hot water heater? and if so would make sense to?

MAC,
This is a local code question as well as one that is answered by the expansion-tank manufacturer. You need to find out what both say and follow those instructions.

I have a leak on the 90 fitting below the expansion tank.I have a shut off valve above the tee that runs to the expansion tank. I will shut the valve off then cut the copper and solder together new fittings. Will i have to pump up the expansion tank again or will itkeep its pressure.
Thanks

What do i have to turn off to the water heater when i replace some of the copper fittings that run to the expansion tank. I have shut off valve above the tee that runs to the expansion tank. Is that the only valve i have to close before i cut the copper.

Thanks

Mike,
The answer is maybe.......

Mike,
You need to stop and take a deep breath. Then go read all of my past columns about soldering copper. Your answers are there.

How long can I expect an expansion tank to last, what type of warranty do they normally carry?

There is a valve above a tee fitting that runs over to the expansion tank. Is that the only valve i need to shut off in order to replace the tank

Roberta,
It is common for them to last as long as the heater. What did you discover when you went to the websites of the expansion-tank manufacturers?

Missy,
Um, not really. That will shut off the cold water to the heater, but water will backfeed through the heater to the fitting. There should have been a separate ball valve on the branch to the expansion tank. Idiot plumber....... Ball valves cost the same as a Value Meal.......

I have a well pump set at roughly 60 PSI that is feeding a "dummy" hot water tank (that I assume once heated water, but is now just holding cold water--it has no electrical connection to it) that is in series with my electric hot water heater. Can you tell me if the first tank serves as an expansion tank of sorts? If this first tank eventually springs a leak, I would guess it would be prudent to put an expansion tank in it's place? (I mean schematically--the expansion tank would be much smaller physically). Thanks for any input you can provide!!

Al,
It is not an expansion tank.

had a pipe break due to my water pressure being at 90lbs, changed the water pressure meter coming into the house also installed a new water heater,and a expansion tank, the problen is that over night the pressure still builds back up to 90lbs, what else can I do to bring down the pressure ?

My expansion tank is leaking, it is upside down is this correct? I want to know before I put in the other one.
Thanks

I currently have an expansion tank installed on the hot water outflow from the water heater. Do I need to move this to the cold water supply line, or will it be okay left where it is?

I removed an expansion tank and it was half full of water. Is this normal? Can I drain the tank and reattach it or must I replace the tank?

I'm installing an electric water heater in my house this weekend. The house always had an oil burner w/boiler but I've converted to wood heat and removed the boiler. I have a drilled well with a large tank in the basement which supplies my water thru a sediment filter.
My question is, do I need an expansion tank when I install the heater, and is there anything else I need to install in the lines to the heater to protect my water supply and the heater.
I'm not concerned with water hammer, I havent had an issue with it before and my boiler was always cranked to the max hot water temp.

HELLO TIM,WOULD YOU PLEASE TELL ME
WHAT WOULD MAKE MY HOT WATER TANK SO HOT
IT SPRAYS WATER OUT OF THE TPV I REPLACED THE TOP THERMASTATE,AND TURN THE LOWER ONE DOWN TO ABOUT 115. THIS IS AN 30 GAL ELECTRIC HOT WATER HEATER
AND IT STILL DOING IT.WHAT COULD CAUSE THIS?
THANKS TIM AND GOD BLESS
ROBERT

so the air valve on the end, is it for bleeding excess air for the proper mix, or is it for charging air into it?

I recently had an expansion tank installed to correct high pressure buildup at times as high as 180 psi after the water heater was running. The plumber installed a tee fitting in the vertical cold water line and about 12 inches of horizontal pipe out to the tank. He used a strap around the tank to attach it to the wall but it is loose from the wall. The weight of the tank is completely supported by the tee fitting. This sounds like an accident waiting to happen. The plumber said that no water goes into the tank and it was fine as is. Do I have reason to be concerned that this is an accident waiting to happen and could break loose at the tee fitting??

can I use an expansion tank on a drilled well system? how would it work if my pump kicks on at 40 psi and off at 70psi and the expansion tank is set at 45 psi?

Is there such a thing as a HWH expansion tank thermal blanket for insulator to reduce heat loss from expansion tank? Thanks

A technician came to my home from a warranty company saying that he couldn't install my new hot water heater which was covered until he installed an expansion tank to bring my home up-to-code. Is this true? Also, do I need an expansion tank when my entire house runs on electric? Lastly, he was "trying" to charge me $75 for the expansion tank and $350 for a ball valve. Is that over priced and necessary? Thank you in advance!

I have an expansion tank diagnostic question for anyone out there: My expansion tank was built/installed in 1992 (I think, based on numbers on the tank label). How long should it last? There is a schrader valve at the bottom of the tank and I pushed the valve in very briefly and WATER came out of it. Does this mean that the bladder/diaphram is ruptured? Thank you.

I have an existing 75 gal gas hot water heater. My system has a backflow preventor and an expansion tank on the cold water side. Recently I needed to replace my temperature and pressure valve because it was opened and gunk got in the seat and it would not close completely. I installed a new T&P valve and now I noticed that the system dribbles water from the t&P valve everytime the heating cycle is on. I replace the T&P valve thinking it was defective but it wasn't the problem is still occurring. Could their be something wrong with my expansion tank? How do I check it for performance. I opened the valve on the bottom of the expansion tank and water came out. Is this correct or has the bladder broken?
Thanks for your help.

I drained my hot water tank(50 Gal.elec)based on a recommendation to do this periodically. I had no problems w/ the pressure or heating of the water. After I drained it the pressure for hot water only, dropped to the point that when I open another faucet the water in both just trickle....i.e., no to little pressure. I checked the expansion tank outlet and the fitting (cap over the valve) was loose. I pressed down on the stem and a very small mount of air,minisule,came out. Any suggestions.
Thank you, Tony

I want a place hot water heater expansion tank, according to the article the tank is placed in the cold line before the Hot water heater. Is that correct ?
And do I have to shut down and drain the hotwater tank to install the tank ??

Need some help, I have a pressure relief valve on my water heater that is probably working correctly. It currently has water dripping from it which leads me to believe I may have a bad expansion tank. I had this same issue a couple years ago and the plumber who install the system when my house was built indicated that the expansion tank had gone bad. now it;d happening again.I want to understand what causes these small tanks to fail. My home is about 7yrs old. Also, how difficult is it to replace and is it dangerious to replace?

I recently installed a new 50 gal. gas water heater with an expansion tank. Now hot water is back feeding to the meter and running up my water bill. What are the most common causes of this problem?

Is it required to install a check valve on the supply line of a hot water heater?Thanks

i installed expansion tank with 40 psi after completion i re checked psi it was 100 psi why is that thank you

hi there
i believe the expansion vessel has to be 'filled' before connection? and that it shoudl be above the storage tank? (in the UK)

how does one fill it first?

thansk

I'm in the process of buying a house at 9000ft in colorado that's very,very cold.

Is there something I need to do to heat the expansion tank??

I have been in the crawl space, and they have old heating tapes all over the place, and seems they have had freezing problems in the past.

I have 2 1/4 bathrooms. The hot water is consistently hot throughout the whole house except in the master bathroom shower. The sink is o.k. Can you tell me why?

My house is fitted w/ an expansion tank (built in 2002) but the pipes "bang" when the washing machines' hot water begins its' cycle. I tried opening and closing the water valve for the washer but that had no effect. What might be a solution- our pipes sound awful!!!

Hi, Wondering if you could help me. Water was pouring through my daughters ceiling when a plumber attending he said it was the feeding expansion tank causing the problem and that it was also over heating.
My husband wants to re do the tank but i would need to get a heating engineer for the over heating side of thinks wouldnt i.
Is the tank easy enough to fit yourself or would it be a plumber that would need to do this

When installing an expansion tank should the installer place a ball valve or shut off valve between the point of connection and the expansion tank for easy replacement in case of failure?

1)under what water pressures is it that i need to install an expansion tank?
2)Can I just not install an expansion tank if I don't bother installing a check valve, back flow preventer or a pressure reducing valve?

Expansion tank for a hot water tank

I replace the exspanion tank on my water line three months ago...already leaking at seam ???

Installed a new tank today...

shut off main, opened a faust, screwed new tank in and turned water back on.


I had to remove the tank and reinstall since it was still leaking slightly...second time, no leak and water running fine.


All the instructions about PSI/ pressure is a little confusing to a non plumbler...


did I miss anything...

sure I check pressure...

Thanks for your help,

Steve

When I install a 5 gal expansion tank on a new heater, is it accepable to put a galvanized "T" on the cold water inlet nipple and mount the expansion tank above the heater (with the cold water entering from the side?

Having problems with hot water heater. It makes a vibrating noise, the cold line sweats, and it is dripping water out the overflow. Please advies, heater is about 4 years old. I have replaced the expansion tank a year ago. THANKS Bob

i assume that your grundfos circ pump is running all the time?
thats the reason you dont have enough h/w..your system is not meant to run like that..the pump should only come on when you need h/m..what happens is the stat gets
:fooled; by the hot watercoming into tank..and does not come on
have your pump hooked up to a motion sencer or tied into your lights,

should the expansion tank be installed on the supply line to the heater, or the line coming out of the water heater?

We have a gas hot water heater. About 15 months ago a plumber installed an expansion tank to eliminate water dripping from all the faucets and showers when the hot water heater was running. Now the dripping is back. What does this mean?

I RECENTLY INSTALLED A NEW ELECTRIC HOT WATER TANK. AIR SEEMS TO BE SPITTING OUT THE HOT WATER FAUCETS AT TIMES, LIKE MY WATER SUPPLY FROM MY WELL WAS LOW.. I DO NOT HAVE AN EXPANSION TANK INSTALLED. IS THIS MY PROBLEM?

I have a tankless hot water heater and am having work done in my bathroom. The contractor says I have to have an "expansion tank" installed on the tankless hot water heater. Is this true that tankless hot water heaters need an expansion tank? What kind of maintenance do you need to do to the expansion tank?

We got a safety inspection done to our water heater and ever since its been leaking from the pipe TMP valve is attatched to. Plumber said that the expansion is not working. But it was working fine ( i think because we didnt have any problems) before he flushed water while doing his safety inspection...would you say that he messed it up? I dont understand if expansion tank was not working why wasn't it leaking before...

Thank You
Neha

I am replacing my water heater and pressure tank. The original expansion tank is on the hot water side of the water heater, is this correct. All the info says to place on cold side.

HOW DO YOU CHARGE AN EXSPANSION TANK

Can a hot water expansion tank be installed after the pressure regulator and before a water softener?

i have a tankless water heater in my house, the pressure is about 95 psi, when the toilet or shower is used, then turned off, the pressure spikes to 110 psi, then the relief valve starts leaking. would a espansion tank on the cold water side solve this problem??
thanks

IM A LITTTLE CONFUSED ABOUT THE INFO I READ ON HERE PERTAINNING TO EXPANSION TANKS DONT YOU HAVE TO PUT ONE ON A DOMESTIC BOOSTER PUMP AND THE HOT WATER HEATER INLET SIDE AND IF SO ARE THEY THE SAME OR ARE THEY CALLED SOMETHING DIFFERENT

If the water pressure from the city line has increased, what the best solution a pressure reducing valve or expansion tank? Increased pressure causing pop-off valve to open.

I replaced the cold water valve on my water heater in the process the expansion tank lost some water.Could this be the reason that the pressure relief valve is now releasing pressure when it was not before and how do I rectify the situation?

what is the proper way to drain a hot water tank when you have an expansion tank , will you lose pressure...

Hi,

My water heater shuts down. I 've replaced the tpr valve recently. When the heater shuts down there is a little water released by the tpr valve. Could this be due to a problem with my expansion tank?

I have two water heaters. Do I need an expansion tank for each one?

I have a 119 gal storage tank
100 ft of 2 1/2 " copper pipe
100 ft of 1 1/2" copper pipe
100 ft of 3/4" copper pipe
On my system
65 PSI
Heated with a Raypak boiler
What should my expansion tank size be?

I had a plumber buddy install an expansion tank to eliminate pipe hammer. He isn't too familiar with these tanks so I gathered info and relayed to him what I had heard. He T'd off of the pressure relief valve(before the actual valve) and I still have the hammering, typically when the washing machine cuts on and off, mostly the hot water side. Is there a problem T-ing off of the pressure valve?

We just had a 2 gallon expansion tank added to our home when we were brought up to code. (New water tank needed) I hear the pipes or the tank under the house filling up or sounds like air bubbles feeding through it. It can do it every 45 seconds-minute. Is it installed properly?

I live in a condo that had shared meters. 2 yrs ago we decideded to go to individual meters.A 35 yr old commnity,Aqua charged us $500 a household to install this and told us all we had to have expansion tanks,included in the price.We never had problems and did we need expansion tanks? My plumber told me today this was $10.plastic tank and aqua ripped us all off.It actually took the guy and hour to install. So I figure aqua made $60,000.00 to install service and expansion tanks individually. ON top we get charged a monthly fee to rent the meter@13.00 a month. Is this I should take up with the BBB?

my old tank is rusting, and i want to replace it but the old tank is installed upside down will this effect the new one if i replace it the same way?

Question: just installed the expansion tank on the cold water side off a tee. want to also place a ck value on the heater lines.
would it benefit me to put one at the wall where the cold water comes into the house to the heater or on the wall where the hot water comes out of heater and goes to the house use??. had a issue where heavy use outside of water, caused a flow out of the heater in the house?>? any comments on resolve?

My house is on well water and 10yrs old, the tank is weeping through a rust hole. Do I really need one of these? My old house (20yrs old) did not have one and since there is a huge pressure tank for the well it should deal with any expansion.

IF I HAVE 2 NEW 50 GALLON HOT WATER TANKS THAT ARE LEAKING WATER FROM THE PRV, DO I NEED 2 EXPANSION TANKS? THANK YOU AND GOD BLESS!

I'm a private citizen having problem with a safety relief valve on my hot water tank.

The problem that I have is everytime we use alot of hot water, like the washer and doing dishes, the pressure relief valve leaks. The water heater is only about 2 years old and this one has an expansion tank. I have changed the pressure relief valve and still have the same problem. Could there be something wrong with the expansion tank?

I had a new water heater and expansion tank installed about two months ago, now the tee fitting above the expansion tank is leaking and sometimes making noice... could this just be a bad hookup or could it be a larger problem like the plumber not installing the correctly sized expansion tank? Any suggestions on how to fix it?

Well,
if membrane fails, don't hurry to pay for a new tank. It will last another 5 years. As a permanent solution, hang the old one bottom up, connect to Tee with a flexible hose, and this is it. Air cushion over the water level is more reliable than any membrane.
Next, the less the pressure, the better, as long as "feet of water column" match to house hight. You can add pressure with bicycle tire pump.
Math: empty tank= 0 atm = 0 psi
when you let system go, water comes into tank
half volume ~ 1atm ~ 15 psi
pressure=1/volume






iPhone!


half full tank ~ 2 atm ~ 15 psi

Vince,
I had the same problem. System hypertension... Check pressure in expansion tank, just like you do with car tires. If zero, follow my prev post

You say the tee should be pointed to the sky, all copper cold water pipes are attached to floor joices. what is my solution. Thank you

I can send photo of my solution

Please explain why you recommend installing the expansion tank above the cold water line, never below it. I checked the Ruud ThermXGuard RRT-5 installatioin instructions; their drawing shows it below the line. I can't see gravity having any affect on a water line pressurized to 30 - 60 psi.

You are absolutely right, neither gravity nor crap accumulation are meaningful.
What "specialists" recommend is keeping water above the rubber membrane inside the tank, and compressed air under membrane.
After afew years membrane fails, air escapes upward into the system, tank fills with water, hangs on your tee pipe like a 50 kg of dead weight, any volume expansion of heated water goes direct to your floor through pressure release valve, and "specialists" get paid for "saving you".
What irecommend is not putting tank above or below, but to connect it to tee via flexible pipe, like you connect your hot water faucet, and hang it near, bottom up and neck down,
it is absolutely reliable regardless of membrane inside

I need to replace my leaky expansion tank and it had been soddered on previously, is there any way to remove it and replave it myself w/out damaging the pipes or should a professional take care of this?

I have a Zilmet expansion tank on my central heating. When I open the valves to allow the mains supply to it, it will not increase in pressur eon the guage. With another I have i a different building when I do this the pressure rises until I close th mains supply valve, why is this happening. I trued to bleed the aire from the bottom of the vessel, was this a mistake. This was only after my other tries at getting hte pressure to rise had failed.
Thanks.
John Chubb

Hi,
i'm making an experimental rig (setup) where i need to use something to depressurise the system without releasing it to atmosphere. can expansion vessel be used as pressure release system the setup?

My expansion tank is leaking at the connection. do I need a new tank, or just reapply some new teflon tape and screw back on?

Can I install the expansion tank directly to the cold water side of hot water heater and tee the cold water supply line to the tank? The expansion tank would be in the vertical position and the hot water heater will be able to support the weight of the expansion tank.

I just installed a new hot water heater. I put the old expansion tank back on and the pvc going to the tank burst. I do not have the opertaing manual for the tank. Does it have to be pressurized while the hot water heater is empty or full? Would not pressurizing it cause it to burst the pvc connected to it?

Received advice from plumbing isle employee at the big box store today, that I should pressurize the expansion tank to 10psi ABOVE my home pressure…..why would this be better/worse than matching psi’s? thanks in advance!

According to the plumber, the bladder probably ruptured in my expansion tank causing it to fill with water and be heavy and thereby crimping the thick plastic (I think) line it was hanging from. He said it didn't matter if I replaced it or not. That sounds wrong to me, but I'm not a plumber. What problems may happen if I don't replace it and how likely are they?

My water expansion tank concetion tub burst, plumber came out said my psi was over 120 what could cause this? is it easy to replace the tubing? it this something that I can do or does this need to be done by a plumber? also the regulator is not working the plumber stated, can I also do this myself or do I need a plumber? If I can do myself were can I find a how to fix for this?

i have a 40 gal hot water tank ( gas ) after showering and using the hot water, the tank fills, just as the heat is about to shut off the pressure/heat valve starts to drip, it does drip for about two minutes after it is shut off, will this tank fix the problem?

Do hot water heater expansion tanks need recalibrated every year? The company that istalled ours wants to come back and perform this service. I do not want to spend money that is not needed. Is this something that needs done?