Loss of water pressure

I recently installed a new expansion tank because I was getting air in the lines after sitting a few hours. Now after sitting a few hours I still get air in the lines. My water will runs til the pump kicks on than I will lose pressure for a second or two before the pressure begins again. Any ideas what could cause this? This only happens after it sits for a few hours

 

It sounds as if you have two problems. The pump doesn't come on when it should and then you have air in the water. The tank won't have anything to do with either, as you've seen by replacing your tank.

My guess is that you have a leak between the pressure tank and the check or foot valve in the well. To prove the theory, shut off your water on the house side of the pressure tank and watch the pressure gauge. If the pressure falls, I'm right. If not, then describe your pump, well and problems in more detail. Like how much air and if the water stops before the pump comes on when you're using water, what type pump and if the pump runs when you aren't using water etc..

Did you check the air pressure in the new tank to be 1-2 psi below the turn on the pump switch setting?

Gary
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Doug Aleshire, Super Moderator 2

 

Hi br317,
- to just add one item to Gary's excellent advice. Please let us know if your pressure switch is on the tank or on the rear of a jetpump, and if you changed the P/S while changing the tank

Do it Right - Do it once.