Noise from my PUMP, PISTON 275GPH 1/3HP when trying to shut off

My husband just installed a new pump, hot water tank, and water softener. Everything works great, we have water and hot water and the water softener seems to work great. however last night while he took his shower and the piston pump was working, it started to make this loud typewriter sound when trying to shut off. I have looked everywhere for a manual to try to fix it ourselves and nothing. could someone please help. It's very loud and it's right before the pump shuts off.
Thanks in advance for the help.

joaniemusic13 said:

loud typewriter sound when trying to shut off.

Click to expand...

Your water system oscillates. My WAG as to the reason would be from water hammer
or
not enough hysteresis - that is, more PSI or more time between turn-on and turn-off.
As a troubleshooting step you could try adjusting this.

How far is the pressure switch from the pressure tank? If it is too far away, many times it will cause the switch to chatter when it cuts out.

The pump is right beside the pressure tank. Also noticed that there is water in the gauge, could that effect the pressure??

it does now sometimes when it starts, but most times when it shuts off. So your saying we should either decrease or increase pressure???

Your pump is a positive displacement type which tend to supply what the pump people classify as "constant" flow. Each piston stroke gives you the same volume. The other types are more nearly constant pressure.
Since water is incompressible I'd think your type would have this kind of problem more often.

Maybe looking at the pump curve and seeing where your operating point lies will give some clue. This example curve was readily available
http://www.aquadirect.com/store/images/d_592.jpg
You'll need a pressure gauge and a flowmeter.

Or you could gamble and install a water hammer arrestor.

"it does now sometimes when it starts, but most times when it shuts off."
If these are these both times when the pressure is below normal it sounds like higher pressure will lessen the problem.

I know that with fans, depending on the fan curve, there are areas of operation as far as airflow and pressure that are forbidden because the fan will oscillate between two operating points, each of which are unstable.

It sounds like this problem has something to teach, assuming we solve it.

before you over complicate things.. what does the pump cut in and out on? 20-40? 30-50? 40-60?... whatever that setting.. does your tank have a bladder? is it adjusted to 2 psi less than the pump cutin pressure? .. do the basics first.

Yes we have a bladder tank. My husband will be looking at it today once he wakes up. Thank you so much for all your help. I think we have it set for 50psi but i'm not really sure. My husband set it up and I believe that is what it's set for. 30-50psi. Does that make sense??? I'll keep you posted as to what happens. thanks again for all you help. New pumps who would have thought it was so complex???

if the switch is set to cut in at 30 and out at 50.. there should be 28psi in the bladder tank when the power is off and all water is drained out of the system.