Intermittent Low Pressure, "Lagging" Sound Well Pump

[wcp]

I have a well for my home water supply. The water pressure and supply have been fine for the last 10-years (the house is 12-years old). Yesterday, I turned on the lawn sprinkler and my daughter was taking a shower at the same time. I noticed very low pressure when I then turned on a faucet. I went to the tank/piping inlet from the pump and the sound was different than normal. There is normally a distinct and clear activation of the pump, consistent clicking of the pump (relay) while the pump is operating, and a clear shut-off of the pump. In this case, the clicking was faint and intermittent, as if the pump was trying to "catch up". It faded in and out and the pressure at the inlet was ~20-psi. I also heard "slugs" in the line, as if there was intermittent air passing through. I shut off the lawn water and then the house water at the supply. Again, the clicking was faint, but the pressure slowly built up to ~60-psi and the pump shut off. We then used water normally, but not excessively, and the pressure seemed OK (I didn't monitor sounds or operation at the tank). Today, I turned the other lawn sprinkler on while my wife was washing clothes and noticed the extreme drop again. At the tank, I heard the same sounds as yesterday. Any thoughts?

[Gary Slusser]

Assuming a submersible pump. Possibly a water leak in the drop pipe in the well. If you do not have a check valve at the pressure tank, shut off the water to the house and watch the pressure gauge over like 30 minutes. If the pressure falls it proves a leak. If not, you may have a leak on the house side of the shut off valve. So with no water use, watch the gauge again and if it falls, you have a leak on the house side which would include the irrigation.

If you have a check valve at the pressure tank, remove it, they are usually installed where there is no need for one or, if there is a leak as a temporary 'fix' which is wrong but it's done instead of pulling the pump and fixing the leak.

[ballvalve]

If you are getting air during the pumps run time, a well running low on water would be be my first thought. "Consistent clicking" of a relay during the operating time of a pump is very abnormal in my book.

Better not pull a check valve at the tank area unless you are sure its not a plain tank, in which case the air you hear is a planned introduction from a valve in the well. In THAT case you would hear air coming in only when the pump starts. Air glugs deep into run time means you are pumping air.

If this is an above ground pump, its another story.