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Community and Q&A

Well pressure tank: In house or separate well house?

brentwilson | Posted in General Questions on

Climate Zone 6B

Should a well pressure tank be located inside the main-floor mechanical room of a house, or in a separate well house outbuilding? An outbuilding would require sufficient insulation and potentially a heat source to keep things from freezing in the winter. Locating the pressure tank indoors could introduce some condensation concerns, as well as the potential for introducing any bad smells the water might have into the interior of the house.

So, which way would you go, and why? Convince me!

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  1. Mike Theis | | #1

    It 's cheaper.
    There would be no condensation is the space in your house is conditioned. And or insulate the tank.
    Smelly Water ??? The water does not vent till you open the tap.

  2. Expert Member
    Zephyr7 | | #2

    Put the tank inside. You can insulate the tank if you’re worried about condensation, or just put a drip pan under the tank. Outdoor tanks, especially in areas with freeze concerns, are just asking for trouble.

    You won’t get any smells through the tank wall since it’s sealed.


  3. Debra Graff | | #3

    I would not put the pressure tank inside the home. I had once done that with a house that I had built on posts. But the tank developed a serious mold problem due to the cold well water sitting inside it on humid summer days. I could not see the condensation causing the mold (though I could clearly smell it), as it was inside the supporting base of the tank. I became very ill due to that mold exposure, though I didn't find out the cause for a long time.

    1. Expert Member
      Zephyr7 | | #7

      Insulating the tank will eliminate any condensation issues. A small spray foam kit will work for that. There is also a heavily textured black paint that can reduce, but not eliminate, condensation issues. I can’t remember the name of that paint, unfortunately.


  4. Expert Member
    Akos | | #4

    At the cottage I needed to build a larger enclosure to also house the jet pump, so it made sense to put the tank out there. Outdoor mounted, there is a chance that with a long enough power outage in very cold weather, things can freeze, so there is chance of freeze damage. It does also sweat a lot in the summer time.

    Generally smaller enclosure the easier it is to insulate and heat, so if you have a deep well pump and your don't need such a large enclosure, I would put it inside the house. Just make sure to insulate at least the bottom half of the tank. As with any water tank it should be installed over a drip pan so you can catch any leaks before they become a problem.

  5. Walter Ahlgrim | | #5

    The choice depends on the depth of the well and the pump choice.

    If you have a deep well with a submersible pump I would put the tank in the house.

    If your well is shallow with a above ground tank then a well house begins to make sense.

    In my part of the country I do not see any new well houses only old ones.


  6. Trevor Chadwick | | #6

    Well, or pump houses are non existent in this part of the country. The pressure tank almost always goes in the house, and the water line is 4' below the surface to prevent freezing.

    Modern tanks are lined, the water doesn't touch the metal, I've never seen condensation on one, and ours is in a damp basement.

    How could the water introduce bad smells????

  7. Expert Member
    Zephyr7 | | #8

    You do have a third option: bury the tank outdoors below the frost line. I had a well driller install a tank that way once. I don’t particularly like that method since it makes service a big deal (dig up the tank, etc) if you ever have any issues, but it does solve the “where to put it” and “what about condensation” issues.

    I suspect underground installation requires a special type of pressure tank. You’ll want to check on that if you decide to go with a buried tank. In my case, the buried tank was installed by the well contractor when the well was drilled and I wasn’t onsite when that work was done.


  8. Trevor Lambert | | #9

    I installed the pressure tank inside the house and saw no condensation on it, despite going the whole first summer with no a/c. I'm guessing it's insulated. The pipes coming off it sweated like crazy before I insulated them.

    1. Expert Member
      Zephyr7 | | #10

      The tanks usually aren’t insulated unless you add insulation yourself. What can change the amount of condensation is how much water is actually in the tank, and how much of the tank is filled by the air bladder. The tank will also typically have a thicker wall than metal pipe (unless you’re using galvanized steel pipe), so it’s somewhat less thermally conductive than the typical copper pipe.

      The other thing is that the amount of condensation you get is heavily dependent on your indoor humidity levels and delivered well water temperature. My well water comes up pretty cold, but the pipe from my well to the tank isn’t particularly long. I've never had an issue with condensation though, at least not enough to notice. I do have a dehumidifier running in the basement which I’m sure helps.


  9. DCContrarian | | #11

    In the house. Condensation is the only issue and it's solvable either through insulation or dehumidification. The house is space you've already paid to build and are already paying to condition.

    Well houses tend to be small and cramped and damp. Just horrid places to work if you ever have an issue. Equipment tends not to last as long because of the dampness.

  10. Stephen Sheehy | | #12

    My house is in Maine. Pressure tank is in the mechanical/ laundry room. Never had a drop of condensation, even though well water comes in at around 50° F.

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