Low pressure

[Bamafan11]

I installed a CSV125-1 valve several months ago.  My system uses a 1 HP shallow well jet pump along with a 7 gallon pressure tank. Cut on pressure is 30 psi and cut off pressure is 50. When first installed, CSV held pressure at 40 psi while continually running to operate my air to water heat pump. Over the past couple of months,  I have seen a gradual pressure reduction down to 28 psi while continuously running. When demand ends, it pumps back up to 50 psi. Any ideas about what’s going on?

[Cary Austin]

Below 40 PSI a 40 PSI Cycle Stop Valve is wide open like a piece of pipe.  If the pressure is dropping to 28 PSI either the pump is not producing as much as it should or the well depth and volume are not adequate.  Sounds like a drop in the water level?

[Bamafan11]

I don’t Know Cary. My well is over 400 deep into the Floridan Aquifer. The well flows with enough pressure without a pump  to shower downstairs. The  pump was new when I installed the CSV, so hopefully it’s ok. If there is not enough water, wouldn’t the pump cavitate or make an odd noise. The pump is running smooth. I’m hoping for an education.

[Cary Austin]

Well your well maybe 400' deep and the water level is at the surface or even flowing, but a shallow well jet can still only access water from 24' deep or less.  If the water level is pulling down to 24', the pump is running out of water.  Could also be a suction leak, but usually won't build back up to 50 after losing prime from a leak.  Can you check the water level in the well when the pressure is low?

[Bamafan11]

I don’t know how I could check the water level at low pressure. Must be water at pump or couldn’t get 28 psi, could I? If pump is running out of water, do you think would there be an audible difference in the sound of the pump?

[Cary Austin]

Not until it completely runs out of water and cavitates will it make noise.  You can put a gauge prior to the CSV to see that you only have 28 PSI there also, and the pump is not producing enough water.  Either the pump is weak or the well is drawing down.

[Bamafan11]

I agree. I was thinking it could be the pump, but it’s only a few months old and it pumps back up to 50 with no problem after demand is gone. How do I test that a pump good? I’ll do some troubleshooting and report back.

[Cary Austin]

Usually building back up to 50 and shutting off is testing the pump, and it sounds ok.  Best way though is to suck water out of a bucket or barrel and put the hose back in the bucket.  Spinning water around in the bucket lets the pump have all the water it needs to test the flow rate at like 40 PSI?