Plumbing question - Expansion tank(s)

bczoom

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Staff member
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When I bought my house, it was on well water and has the larger (probably 30 gallon or so) pressure tank.

Although the well system is still operational, we've switched to city water. In doing so, that pressure tank is no longer in play.

Do I assume correctly that the pressure tank acted as the expansion tank for the hot water? Now that it's not in use, should I install one to accommodate the hot water expansion?

Mrs. Zoom had me install one of those kitchen faucets that have touch control. (just touch any part of it to turn the water on or off). When that touch system is being used, you can hear the pipes banging a bit when the water is turned off. I'm assuming that's a shock to the system.

If I install an expansion tank on the cold water side of the hot water tank near that kitchen faucet, would that take care of everything?

===water supply===kitchen cold===pressure tank===cold water side of HW tank.
 

Doc

Administrator
Staff member
Brian, I'm far from an expert on this, but years ago I did work with well systems. Pressure tanks were to help maintain pressure in the house when you had a constant draw on the water. Like when you were showering. The well pump would pump up enough water to fill that need prior to you needing it, then when you used a bunch of water it was not as hard on the pump.

Sounds like you simply have what I think it called water hammering. Guessig you have copper pipes and one is loose and banging against the other that is close by, or banging something else.

all just my 2 cents .... hope it helps.
 

FrancSevin

Proudly Deplorable
GOLD Site Supporter
When I bought my house, it was on well water and has the larger (probably 30 gallon or so) pressure tank.

Although the well system is still operational, we've switched to city water. In doing so, that pressure tank is no longer in play.

Do I assume correctly that the pressure tank acted as the expansion tank for the hot water? Now that it's not in use, should I install one to accommodate the hot water expansion?

Mrs. Zoom had me install one of those kitchen faucets that have touch control. (just touch any part of it to turn the water on or off). When that touch system is being used, you can hear the pipes banging a bit when the water is turned off. I'm assuming that's a shock to the system.

If I install an expansion tank on the cold water side of the hot water tank near that kitchen faucet, would that take care of everything?
.

===water supply===kitchen cold===pressure tank===cold water side of HW tank.


Yes. Do it at least three feet (Of the level pipe) from the cold water intake inlet to the Hot Water heater
 

BigAl

New member
SUPER Site Supporter
When I bought my house, it was on well water and has the larger (probably 30 gallon or so) pressure tank.

Although the well system is still operational, we've switched to city water. In doing so, that pressure tank is no longer in play.

Do I assume correctly that the pressure tank acted as the expansion tank for the hot water? Now that it's not in use, should I install one to accommodate the hot water expansion?

Mrs. Zoom had me install one of those kitchen faucets that have touch control. (just touch any part of it to turn the water on or off). When that touch system is being used, you can hear the pipes banging a bit when the water is turned off. I'm assuming that's a shock to the system.

If I install an expansion tank on the cold water side of the hot water tank near that kitchen faucet, would that take care of everything?

===water supply===kitchen cold===pressure tank===cold water side of HW tank.

Boomer ,
What you have going on is called hammering . It is caused by water lines that have shut off valves like washers that instantly shut off the water . What you can do is install some water bumpers to stop this . It is basically a shock absorber for water that has air in it . You can buy them cheap at home depopt or make your own out of a piece of pipe and a cap on one end . They need to stand vertical . The pressure tank can be eliminated now that you are on city water . That was for steady pressure only .
 

Dargo

Like a bad penny...
GOLD Site Supporter
A pressure tank on a well mostly serves as a reserve supply of water so your expensive, and difficult to access, well pump does not have to cycle on and off each time some amount of water is used. It likely has a switch where it kicks the well pump on when it is down to 15 gallons or so and then refills. It also helps with providing more pressure on well systems.

At our last house our water well was about 350' deep. Even with a 240 volt 2 hp pump, it really had little volume or pressure at ground level. I had an adjustable air bladder that provided force on our water tank which, mostly, allowed us to take showers with more than just a dribble of water coming out. If I wanted more pressure, I could just use my air compressor to have the air bladder push harder on the water in the tank. The trade off was that the more pressure I had in the tank, the longer it took for my well pump to force water back into the pressure tank. It's recovery time was more with greater pressure.
 

FrancSevin

Proudly Deplorable
GOLD Site Supporter
An air cushion riser is cheap and effective. However,

Expansion tanks are now code requirements in some areas. My county requires them on all new and replacement water heaters. You might make sure before you try the air cushion riser.
 
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