Test your hot water expansion tank

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imaref

Active Member
I had a new hot water expansion tank installed today during a routine electric hot water heater flush. Plumber showed me how to easily test if your expansion tank has gone bad (which mine had after 10 years)--use the metal end of a screwdriver and lightly tap the expansion tank and it should make a hollow clink sound. If it makes a dull sound instead, it means the bladder inside has failed and the whole tank is filled with water (which will increase the pressure on your water pipes) and needs to be replaced. If you're still not positive, unscrew the bottom cap on the expansion tank and there is a bleeder valve--if you press it quickly you should hear a quick burst of air if the tank is still good. If you get no air or a quick spray of water, you know it's bad.

Just sharing so you can test yours (if you have one).
 
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Clem72

Clem72

Well-Known Member
imaref said:
I had a new hot water expansion tank installed today during a routine electric hot water heater flush. Plumber showed me how to easily test if your expansion tank has gone bad (which mine had after 10 years)--use the metal end of a screwdriver and lightly tap the expansion tank and it should make a hollow clink sound. If it makes a dull sound instead, it means the bladder inside has failed and the whole tank is filled with water (which will increase the pressure on your water pipes) and needs to be replaced. If you're still not positive, unscrew the bottom cap on the expansion tank and there is a bleeder valve--if you press it quickly you should hear a quick burst of air if the tank is still good. If you get no air or a quick spray of water, you know it's bad.

Just sharing so you can test yours (if you have one).
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Or, and hear me out, you could pump the bladder back up and maybe get another 10 years. Do buy new tires every time they get low or do first pump them up to see if they still hold pressure? Sounds like the plumber was trying to make some easy money.
 
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imaref

Active Member
Clem72 said:
Or, and hear me out, you could pump the bladder back up and maybe get another 10 years. Do buy new tires every time they get low or do first pump them up to see if they still hold pressure? Sounds like the plumber was trying to make some easy money.
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In my case, the whole expansion tank was full of water meaning the bladder busted. No amount of pumping the bladder back up would have made any difference but I understand your point.
 
Clem72

Clem72

Well-Known Member
imaref said:
In my case, the whole expansion tank was full of water meaning the bladder busted. No amount of pumping the bladder back up would have made any difference but I understand your point.
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DID YOU TRY RE-INFLATING IT, YES OR NO? Tank full of water does not mean the bladder is busted, it means the bladder is empty (or really just under inflated). It could have emptied because it ruptured, it also could have emptied because rubber is air permeable and with time and pressure the air will always escape. 100 percent of the time. And you admittedly went 10 years without checking and refilling the bladder.
 
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imaref

Active Member
Clem72 said:
DID YOU TRY RE-INFLATING IT, YES OR NO? Tank full of water does not mean the bladder is busted, it means the bladder is empty (or really just under inflated). It could have emptied because it ruptured, it also could have emptied because rubber is air permeable and with time and pressure the air will always escape. 100 percent of the time. And you admittedly went 10 years without checking and refilling the bladder.
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I did not. But when he took off the old tank, removed the jam nut that holds the bladder, pulled out the bladder and it was split in multiple places I was pretty sure that the bladder had failed.
 
LightRoasted

LightRoasted

If I may ...
For your consideration ...

imaref said:
I did not. But when he took off the old tank, removed the jam nut that holds the bladder, pulled out the bladder and it was split in multiple places I was pretty sure that the bladder had failed.
Click to expand...

My bladder failed once. I was wearing brown pants. It was an experience something like doing a good deed. You get that good warm feeling, but nobody notices.
 
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phreddyp

Well-Known Member
black dog said:
If you push the needle in on the air valve when the water has pressure and water squirts out. The bladder has failed.
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Does anyone remember the old captive air well tanks, no bladder just pumped air into the tank when the air leaked out? I would use the same principal on one on the HWH it's only there for the expansion of the water being heated, it doesn't give a rats azz if there is a bladder.
 
black dog

black dog

Free America
phreddyp said:
Does anyone remember the old captive air well tanks, no bladder just pumped air into the tank when the air leaked out? I would use the same principal on one on the HWH it's only there for the expansion of the water being heated, it doesn't give a rats azz if there is a bladder.
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Yep, seen plenty of them. The difference is a few gallons of compressed air and a quart of compressed air.
And with a well when you miss the unbladdered tank having no air pressure the pump will short cycle and fail at a rapid pace.
A good bladder tank is a good investment. With a well or without. So many municipality's have a dual check valve on the water service as it enters a home or building. One needs an expansion tank, it makes water expansion and water hammering much easier on your equipment.
 
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phreddyp

Well-Known Member
black dog said:
Yep, seen plenty of them. The difference is a few gallons of compressed air and a quart of compressed air.
And with a well when you miss the unbladdered tank having no air pressure the pump will short cycle and fail at a rapid pace.
A good bladder tank is a good investment. With a well or without. So many municipality's have a dual check valve on the water service as it enters a home or building. One needs an expansion tank, it makes water expansion and water hammering much easier on your equipment.
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Oh, and it doesn't do that when the bladder fails? As long as the air is still in the tank it shouldn't make any difference whether is in a bladder or not same Schrader valve is holding the air in it. Same amount of air pressure.
 
black dog

black dog

Free America
phreddyp said:
Oh, and it doesn't do that when the bladder fails? As long as the air is still in the tank it shouldn't make any difference whether is in a bladder or not same Schrader valve is holding the air in it. Same amount of air pressure.
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You sound like an office engineer with zip in field experience.
For the love of god, the air without a bladder will dissipate in a short period. There is a reason that well tanks without a bladder went out of style.
Thats just what every home owner wants to do each month, drop water pressure off and use a pump to pressurize a tank to 4 psi over your normal water pressure.
 
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phreddyp

Well-Known Member
black dog said:
You sound like an office engineer with zip in field experience.
For the love of god, the air without a bladder will dissipate in a short period. There is a reason that well tanks without a bladder went out of style.
Thats just what every home owner wants to do each month, drop water pressure off and use a pump to pressurize a tank to 4 psi over your normal water pressure.
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Funny I don't remember pumping the tank up more than once a year, hell I remember when glass lined tanks were the new thing on the block. Before that they were just metal and the water was somewhat rusty at times worked fine then, but improvements are always made. Not to mention piston pumps, of course these were back is the days of shallow wells.No field experience my friend LOL, I've most likely forgotten more than you will ever know young man on a few things.

On and by the way where does the air go, when it dissipates?
 
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black dog

black dog

Free America
phreddyp said:
Funny I don't remember pumping the tank up more than once a year, hell I remember when glass lined tanks were the new thing on the block. Before that they were just metal and the water was somewhat rusty at times worked fine then, but improvements are always made. Not to mention piston pumps, of course these were back is the days of shallow wells.No field experience my friend LOL, I've most likely forgotten more than you will ever know young man on a few things.

On and by the way where does the air go, when it dissipates?
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The water absorbs it, did you not pass 7th grade science?

If it didn't there would be no reason for a bladder.
 
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