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Discussion Starter · #1 ·
Hi,
My Hot Water tank is 8 years old. The pipes upstairs whistle for 3 seconds after the upstairs sink is turned off (the whistle seems like it is from the pipes to the toliet in the same bathroom though). Possibly unrelated.

The whistling has been for 6 months. The water heater has been leaking now for about 2 weeks from the drain pipe from the pressure relief valve. It seems to happen after a hot shower.

The amount is about 2 cups of water and the water heater temperature has always been turned much lower than the recommended (or typical) home setting since we have younger children to prevent scalds.

The water tank has an expansion tank. I tap it and it does not seem hollow...but I am not sure exactly when to tap it...after a hot shower...several hours between hot water use (shower, dish washer, etc.).

How do I do more trouble shooting of the expansion tank and whether the pressure relief valve is going? I have never noticed any constant stream or drip from the relief valve...just notice the two cups fulls in the tubberware that I use to catch the water in. I check it several times a day and defintely seems to correspond to hot water use...but I have not actually waited watching while the shower upstairs was in use :)

what more should I be doing ? Once I get an idea of what is going on....this will be a job for a plumber...not me!

Thanks!
 

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How do I do more trouble shooting of the expansion tank and whether the pressure relief valve is going?
On the bottom of the expansion is a schrader valve. Check the pressure of the exp. tank there with a tire pressure gauge.

Turn off incoming water to wh, open a faucet to release pressure, it should closely match the main incoming water pressure, usually around 50-60 psi or so. if nothing but water comes out of it when checking the pressure, its bad and needs to be replaced. If low, add the appropriate amount of air. Start there. Report back with results. Takes about 5 minutes. Then you can rule that out. thanks.
 

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Wait for the water heater to finish its cycle and kick off. Draw about a half gallon of water from a faucet to remove any remaining influence of the water heater on the water system pressure.

Measure the water system pressure with main water valve turned on all faucets off. You can use either a gauge screwed onto an outside hose bibb or a tire gauge on the water heater expansion tank, or any other water pressure gauge you might already have installed such as for a well system.

With water still turned on, let all of the air out of the expansion tank (to see if water comes out). If water comes out then replace the expansion tank.

With the main water turned off and an upstairs faucet open, pressurize the expansion tank to the water system pressure you measured earlier.

Turn everything back on.
 

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Due to exceeding the 30 minute limit to edit, this post with a few more scattered edits is reposted here in its entirety rather than sort out just the ;syrdy sentences that needed to be changed.

Wait for the water heater to finish its cycle and kick off. Draw about a half gallon of water from a faucet to remove any remaining influence of the water heater on the water system pressure.

Measure the water system pressure with main water valve turned on all faucets off. You can use either a gauge screwed onto an outside hose bibb or a tire gauge on the water heater expansion tank, or any other water pressure gauge you might already have installed such as for a well system.

With water still turned on, let all of the air out of the expansion tank (to see if water comes out). If water comes out then replace the expansion tank.

(You may choose to keep a non-bladder expansion tank which is not common nowadays, is somewhat larger than a typical modern expansion tank, should have its air valve up top, and which will always let out water, but you will need to repeat this procedure periodically, untimately at half the number of weeks it takes for the original problem (water heater relief valve spitting water) to resume.)

With the main water turned off and an upstairs faucet open, pressurize the expansion tank to the water system pressure you measured earlier. (For a non-bladder expansion tank the open faucet will spit air after letting out more water long before you reach system pressure at which time you are done adding air.)

Turn everything back on.
 

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Discussion Starter · #6 ·
Sorry for the delay....I finally got around to testing the expansion tank. Air pressure gauge releases....water. So bad expansion tank. I never realized that one should even test the tank every year or so. Live and learn.

So there is a cold water cutoff valve just upstream of the expansion tank, so how difficult of a job is this?

Also, if the Pres. relief valve just releases a few cups of water after a couple of hot showers....is that still ok?

Do I call a plumber and just have him "Fix"it, or do I order a new tank off of amazon and then just pay for labor? (CC bill will be huge enough with Christmas...sigh).

Thanks again!
 

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There should never be water coming out of the relief valve unless there's an issue.
Why would you order one on line? Any Lowe's Home Depot, plumbing supply will have one in stock.
Shut off the incoming water, open up a faucet to relieve the pressure, unscrew the old one install the new one using pipe Teflon dope, 10 min. fix.
Other things can cause this.
One is to high an incoming water pressure.
Simple and cheap to check, is it city or well water?
If it's city water a simplle cheap valve on an outside faucet can check the pressure.
http://www.homedepot.com/p/Winters-...-and-Range-of-0-160-psi-kPa-PETM213/205962470
There's no need for the pressure to be much more then 50 PSI.
 

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You May not need a new wh yet. Thats up to you.

Its a diy project for less than 50 bucks. You do all the labor.

As mentioned, turn off wh, turn off incoming water to wh, open a couple faucets, drain a couple gallons out of wh to get below temperature pressure relief valve.

Replace exp tank and tpr valve. Set psi on exp tank before installing. Should closely match your incoming water pressure about 50_55psi. Check first with gauge. Replace tpr valve.

After you have replaced tpr valve and exp tank, turn water back on and check for leaks. Once in starts coming out the faucets turn them off. Turn on
and fire up wh.

Check again for leaks. No water should be dripping from tpr valve.

If you dont feel comfortable doing this by all means call a pro. Just remember they usually get 150 dollars or so just to come out. Plus parts, labor, tax, ect.
 

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Discussion Starter · #9 · (Edited)
I missed the 30 minute as well to edit! :)

Its 7.5x 9" not including the threaded connection...how crucial is it to match up the new one to the old one as far as capacity?

Amazon, HD, etc...didn't mean to muddy the waters. HD sometimes doesn't have stuff in stock by me.

There are no markings....it is just a plain white tank with a blue cap, with the air valve below.

Ok....dunce award...since we have a backflow valve for the sprinkler system (local code) there is a nice gauge on the system showing 52 psi...I should have mentioned this.

It is city water....quick replies! :)
Thanks
 

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No one here can see your tank or where your suggesting to test the pressure without a picture.
Any outside faucet should work as long as it's after the pressure reducing valve.
Not crtitcal on the tank size.
Never once seen a tank without some info on the outside of it.
 

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Discussion Starter · #12 ·
52psi on water pressure....it's just a plain white tank..."builder-special" I'm sure. Of course, the builder never mentioned about checking the pressure on the thing.

If size isn't critical, I'll just get something similar...
It seems fairly straight forward.


I do appreciate the information and help.

Thanks.
 

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Discussion Starter · #14 · (Edited)
Ha! After looking more carefully...it appears the builder's plumbing company screwed me again.

The hot water exhaust pipe is 2 inches from the expansion tank....limiting the room I have to work and limiting the size of tank....I basically need an exact size tank.

Nimrods.....why do people do work that sucks.....argh.

Sorry for the rant....now I will have to find a near exact fit tank or re-route the exhaust. wonderful.
 

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It's usually a standard exp. tank for water heater. It should fit.

When you get to the big box store ask specially for a water heater exp. tank. Stay away from the boiler exp. tanks as they will not fit. They are way too big.
 

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Discussion Starter · #16 ·
ok thanks. It seems like the installation made it more complicated than it needs to be.

If I need to re-route the exhaust from the water heater...is that just standard HVAC piping?

Of course, I'm sure there are codes in the number of twists and bends...but is it just a standard HVAC....not any internal insulation or anything?


Thanks
 

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There can be a few feet of pipe between the expansion tank and where it is hooked into the water line, if this helps with positioning and clearance. The expansion tank can be in any position, air valve up is the best.

Regardless of where and how the expansion tank is positioned, it is a good idea to have a tether or other support for it so that if it should fill with water, it won't sag and break off and then the open pipe floods the place.
 

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Discussion Starter · #19 ·
A tether is a great idea...but most likely too "hard" for the builder's plumbers to have done. In other words....the bare minimum...no tether and I just figured out the tank they installed 8 years ago is too small, and undersized for a 75 gal tank!

Friggin idiots. So I will def. need to change the exhaust....

500 K gets you sheet! these days!
 

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Discussion Starter · #20 ·
Ok the proper tank (4.5gal) is huge compared to the builder's. My pressure into the house is....70 psi....I mis-read the gauge previously in this thread.

I have the valve above the water heater closed (no cold water going into tank) I have the hot water heater off...of course and the gas supply shutoff.

I have a faucet open to let the pressure off...someone suggested to be careful with the faucet on the tank since sometimes they get stuck open.....true/not true?

Anyway....it has now been 20 minutes and water still coming out of the faucet on full hot (water temp is cold). How long should it take?

I opened an upstairs faucet and it was disturbing since there was a very loud shriek (at first I thought a fire alarm) from the pipes in the basement...the noise stopped with only a first floor faucet open.

Thoughts or hints?

Thanks
 
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