A few months ago, I posted a thread about my pressure booster system short-cycling. Well, I finally did some more experiments, which I think are conclusive, and I'd like confirmation from experts here.

Municipal water supply, booster system consisting of check valve, jet pump, Well-mate WM-6 bladder tank. Prevously reported observing cut-in at 40psi and cut-out at 45psi. Someone suggested guage might be bad, so I bought a screw-on type and observed during short cycling. Actual cut-in is 40psi and cout-out is 60psi according to new guage. This would seem to rule out pressure switch.

Now, while observing guage, after reaching 60psi, slowly drops back down to around 40psi while no water being used. If I shut off the main valve to the house, the pressure holds steady at 60psi. Open the main, pressure drops back down to around 40psi and short-cycling continues. Note that short-cycling only occurs during periods of heavy water usage in general.

Previously, I had done the test to momentarily release pressure from the tank air valve, and no water came out. My conclusion is that the check valve is malfunctioning either because is has failed or has a blockage. By the way, the water service line was replaced in Nov. '04 and I already had a stone jam one of the toilet fill valves. Perhaps there is a stone in the check valve. So, it seems that the street pressure runs in the low 40's psi right now and fluctuates right around the 40psi mark during heavy usage. Malfunctioning check valve causes short-cycling under these circumstances.

Do the experts here agree with this conclusion? Could it be anything else?

Thanks

 

Follow up to readers. Before I could get an answer from the experts, here, my caretaker (it's a vacaction home) called up to report a leak. During repairt, he took off the check valve at my request and lo and behold, he found 2 stones in it. Problem solved!