Question - Expansion Tank on Hot Water Heater

Discussion in 'General Plumbing Help' started by MichaelB, Dec 9, 2019.

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  1. Dec 9, 2019 #1

    MichaelB

    MichaelB

    MichaelB

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    I recently developed a pin hole on the top of my expansion tank at my hot water heater. I had a friend of the family come replace it. He put the new one on but did not adjust the pre-charged pressure in the tank. Ever since then, I have noticed a notable increase in water pressure in my house. Both toilets actually refill approximately 5-7 seconds faster than before and seem to make a louder noise when shutting off. I can hear a noise in one bathroom as soon as the toilet is flushed that seems to be coming from the wall. I also notice the increased pressure in the sinks, but this is easily controlled becasue of the faucets. I did not have any of these issues before the expansion tank was replaced.

    Could the change in pressure be the result of the new expansion tank pressure not being adjusted or am I just missing something? If it is, is this something that can be easily fixed? I obviously do not want to have any pipe issues if at all possible.

    Thanks for any help or insights.
     
  2. Dec 9, 2019 #2

    Diehard

    Diehard

    Diehard

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    That's quite a coincidence I'd say.
    Should have no affect on your systems normal pressure.

    I would suggest you take any pressure off from the water side of your expansion tank and charge the air pressure to closely match you water system pressure.
    If you don't know what your water pressure is, you can pick up a pressure gauge that's made to hook up to a hose connection and connect to your silcock or washing machine hose valve.

    The air correct pressure maximizes the volume of air in the tank that will be compressed when the water expands.
     
  3. Dec 9, 2019 #3

    MichaelB

    MichaelB

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    What all has to be done to properly charge the air tank to the correct pressure? Is something that can be done easily?
     
  4. Dec 9, 2019 #4

    Diehard

    Diehard

    Diehard

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    Yes it's relatively easy.
    There are many videos on it. Here's one.

    I don't want to confuse you but he method the Watts guy describes is not getting all the pressure off the water side since you still have the hot water pipe full of water.
    In other words, every 2.3 feet of water above the tank represents 1 psi. So if for example you had a 2 story house you could still have say about 7 PSI exerting pressure on that tank.
    Depending on how yours is piped you may be able to avoid that discrepancy. So feel free to post a picture showing the piping around the expansion tank and heater.
    I would just estimate the amount of water pressure is still on that tank and add that amount to my air pressure.
     
  5. Dec 9, 2019 #5

    MichaelB

    MichaelB

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    Thanks
     
  6. Dec 9, 2019 #6

    Diehard

    Diehard

    Diehard

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    In my research for better video I read a lot of Watts comments /replies to peoples questions.
    Apparently if a tank is over pressurized with air you could experience a momentary pressure surge above your normal pressure.
    For example, if your water pressure was 50 psi and the air was set to 60 psi, expansion due to heating the water would allow that water to rise to 60 psi before expansion could take place.So when you open a faucet you could be seeing it going from 60 psi down to 50 psi for a few seconds or so, depending on the size of the tank.
    Just for the hell of it, check the air pressure first.

    EDIT: So maybe that plumber did pressurized it, at some point, at a much high pressure.:eek:
     
    Last edited: Dec 9, 2019
  7. Dec 10, 2019 #7

    Jeff Handy

    Jeff Handy

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    Or you might have a pressure reducing valve on the incoming water supply, which has malfunctioned or needs adjusting.
     
  8. Dec 11, 2019 #8

    callaghanpump

    callaghanpump

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    According to me if you are suffering from these kind of issues like faster water pressure and louder noise then you should replace the new expansion tank pressure with the help of professionals.
     

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