Air in Lines, Low Pressure

[MasterPlumbersKeymaster]

A friend asked my advice on her plumbing problem, but I’m stumped. Maybe you experts can answer the question. Starting about three weeks ago, she has had some air in upstairs faucets every morning, and her pressure fluctuates more than normal when two or more faucets are open. She is on city water, but is so near the elevation of the city tanks that she has a centirfugal pump and pressure tank to keep full pressure (about 40 psi). I thought she had a leak between her pump and the street (or the city had some air in their lines). The city checked and confirmed that everything up to her meter was OK, and she replaced the line from her meter to the pump.

She still has the air and pressure problems, and she also has some standing water under her house that doesn’t appear to be coming from any walls or pipes.

I noticed she is missing a check valve just ahead of the pump, so when the pump kicks on it is pressurizing the tank and the line back to the meter. One other thing… I was at her house the other day when the pumped kicked on and nothing was running in the house, which tells me there’s a leak somewhere (I guess).

She has had two plumbers look at it without success. Any suggestions?

[SylvanLMPParticipant]

Try this, make sure all water is turned off in the house. Then when the pump comes on again SHUT the house main and look at the gauge and see if it drops.

This should tell you if the pump (seals) are leaking. If the seals are leaking this could account for air being sucked into the system.

Now if nothing drops open the main valve and again look for a pressure drop.

There could be the following.

1- The water pressure in the home is greater then the street pressure and this could account for a pressure drop.

2- There could be an under ground leak.

[wpcParticipant]

As far air in the line the pump seal would be the primary source.As far as the pressure changes I would look at the volute of the pump where the impellar is located. You could have sediment in the impeller of the pump. You said the water co. has checked the service to the meter. I would check gauge on inlet to the pump and see if you get the changes in presure. If you do then it may be possible the meter could be causing the problem. Ideally a gauge before @ after the meter would give you this answer.

[wpcParticipant]

I would like to point out that in my earlier response I am assuming that your water meter is at the property line, also placing a pipe nipple in place of the water meter would be eisier to do and would rule out the water meter

[Author]

Posts