Expansion tank - Need increased PSI water pressure


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Old 09-12-07, 03:45 PM
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Expansion tank - Need increased PSI water pressure

I have recently installed a new expansion tank to my hot water heater system -

My system is now fully turned back on and water flowing. However, I have noticed a clear decrease in water pressure.

What is the best to go about increasing my water pressure. My expansion tank has an air intake valve (where a small hand pump can be connected).

But in order to do this....Do I need to shut down my entire hot water system? Or just turn off the water line to the house?

Thanks for any help....
 
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Old 09-12-07, 07:26 PM
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Are you talk hot water for heating your home or hot water for showers?
 
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Old 09-12-07, 07:49 PM
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This is hot water tank for my showers (kitchen, etc).
 
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Old 09-12-07, 08:16 PM
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The expansion tank should have absolutely NO effect on your water pressure. The tank precharge is preset to the existing water pressure from the source of the domestic water..
 
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Old 09-12-07, 08:19 PM
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Check your facet strainers for junk. That often happens when the water is turned off and back on. Lose debris in the system gets flushed and clogs the strainers....

Pete
 
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Old 09-15-07, 10:38 AM
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Hmm. I'm finding it very odd that as soon as I put my new expansion tank in......My water pressure went to hell....

The air pressure gauge (on the expansion tank itself) shows a pressure of 35 PSI (that seems low to me). That seems like it wound effect the water pressure throughout my house.

I know prior....I could have the lanudry running and the shower (for example). Without any problems. Now, if the washer is on.....I get about a trickle coming out of my shower??

My plumbing system is older (though, I have a newer, hot water tank....and brand new expansion tank). My system does not have a presure valve (screw that I can easily adjust).

My concern is....I've read where you should MATCH your expansion tanks air charge with the incoming water pressure.

I am quite certain that my (city water) PSI is higher than 35 PSI - (yet, my city water dept has yet to get back with me on this).

So, if I need to increase my air pressure (of my expansion tank) to MATCH my incoming water pressure.

How do I easily go about this?
 
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Old 09-15-07, 07:03 PM
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Exp. Tank

Where is this expansion tank? Is it on the heating system or for the domestic hot water?
 
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Old 09-15-07, 08:32 PM
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A modern expansion tank has a rubber bladder with an air charge on one side and the system water on the other. Matching the charge pressure to system is not truly necessary. As water pressure drops the bladder pushes water out of the tank, into the system. As water pressure increases, the bladder goes the other way allowing water to fill the tank. A pressure of 35 PSI on the pressure tank indicates that system pressure is 35 PSI. Yes, that is a low pressure reading for city water.

Do you have a pressure reducing valve somewhere in the system? Does the water pressure drop when using cold water as well?

Your symptoms don't, IMO, point to your pressure tank. The INSTALL of the pressure tank could be the culprit. Whenever a water system is entered and then restarted, a certain amount of scale is dislodged in the pipes. It collects on restriction devices in the system, inline strainers, faucet aerators, etc. My guess is that you have a restriction that is causing your entire system to have reduced flow.
 
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Old 09-16-07, 05:54 PM
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Mass confusion..

What kind of tank are we talking about??

Is this a small bladder type expansion tank for the hot water (which holds about 4.4 gallons); it's only function is to protect the system from over pressure because hot water expands and if the house has PRV on the street supply you can end up releasing pressure through the safety valves otherwise.

Or are you talking about a large-sized pressure tank for well water???? Do you have well water or city water? What does this tank do in your system?

If you changed a well water tank you might have crud in the small line going to the pressure sensing switch.
 
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Old 09-16-07, 06:33 PM
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Wink

On small bladder tanks with no Psi on the water side at all the air side here I believe should be 33 lb . 2 lb light of that 35Lb water psi
 
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Old 09-20-07, 06:14 PM
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And he was told _all_ this in several PM's that we exchanged just before this thread started... guess he didn't believe me.
 
 

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