Pressure not building past 40psi

[GregD]

My pump had been cycling frequently and flow at the faucets had been inconsistent, so at the advice of a plumber friend, I replaced the pressure tank. Turns out that was just the the start of this DIY adventure.

After the tank was replaced, the pump started up but would only build to 20 psi. I replaced the check valve on the suction pipe which turned out to be stuck open. The pump was able to get up to 35 psi. I disassembled the pump and cleaned out the jet nozzle and removed the hard water sediments in the pump casing. Afterwards, the Pressure would reach 40 psi but no higher.

there is problem #1 - can’t get pressure to build

when the pressure is at 40 psi, I get decent flow at the outdoor hose faucet and in my shower, but my kitchen and bathroom sinks only dribble out. There was no major problem with those faucets before now so I am wondering if I might have an air lock or maybe some of the hard water sediment that got disturbed during the tank replacement may have travelled up and is clogging the pipes to the sinks.

All pipes are 1/2” pex except for the section between the pump and a manifold maybe 6 feet away which is 3/4” copper. I tried turning off all valves at the manifold so only the kitchen sink line was open, but it made no difference in flow.

There is problem #2 - not sure how to address the low flow on these lines.

shallow well. Grundfos JPF 3-a jet pump.

Any help is appreciated.

Greg

 

[Bannerman]

maybe some of the hard water sediment that got disturbed during the tank replacement may have travelled up and is clogging the pipes to the sinks.

Have you removed the aerator on each faucet to determine if they are clogged with debris? With the aerator removed, open each faucet to allow any additional sediment to be flushed out.

Suggest removing the pump pressure switch and the nipple which supplies water pressure to it. The nipple and the mating connections could be blocked with debris so clean out the nipple and the connections it threads into. If there is blockage, that can prevent the actual water pressure from being correctly sensed by the pressure switch and pressure gauge.

 

[Sponsor]

 

[GregD]

Have you removed the aerator on each faucet to determine if they are clogged with debris? With the aerator removed, open each faucet to allow any additional sediment to be flushed out.

Removed the aerators. No noticeable difference in the flow. The bathroom sink sputtered a bit and now seems to back to normal. The kitchen sink sputtered a bit too, but still only a tiny stream when faucet is wide open.

 

[Valveman]

Most likely you have a suction leak. When the pump runs but won't build enough to shut off, it gets the water hot. The hot water melts the pipe attached to the suction side of the pump and you get an air leak. When you get the air leak fixed and the pump building pressure again, cycling on and off will be the problem. Cycling on and off is what causes check valves to fail and stick, causes tank diaphragms to fail, causes the well to be surged and make more sediment, and will also wear out the pressure switch and pump. Cycling is easy to fix by just adding a Cycle Stop Valve.

 

[GregD]

after checking all pipes and fittings and finding no evidence of leaks, I concluded the pump was in need of replacement. I swapped it out today and instantly got the pressure I was looking for.

As for the kitchen sink ... when I removed the aerators, I didn’t check the cylinder. After a soak in vinegar and a thorough rinse ... I have decent flow again.

Thanks for the responses. This little adventure has taught me quite a bit about my water system.

Cheers,
Greg