Pump Problems

Hi!
Not only am I new to the world of home ownership at the lake, I'm a complete rookie in plumbing, so if people could "dumb down" their responses, I'd appreciate it.
We have a pump, with tank in an indoor area next to the house. The switches are there. We have a line out to the lake.

Our problem is this-the pump was cycling on and off, so we replaced the tank, and it was okay for a while. Now it just won't build pressure at all. It'll go to 49 psi, but won't ever quite reach 50 which is where we have it set to turn off.

Any suggestions as to what I need to look at/for?
And, BTW, what's a "foot valve"?

Told you I was a rookie
Caroline

Do you mean that the pump runs continuously, never getting to the 50 pounds? Or does it stop at 49? The gauges aren't all that accurate, if it does stop and you want it a little higher, adjust the screw in a little bit. Do you have good flow? Could the inlet to the pump be plugged - weeds? sand? other junk?

To Clarify

Hi!
Sorry, I should have clarified that. The pump runs continuously, never getting to 50 psi. How do I go about checking for weeds, etc. in the line? Do I unhook it and shake it out? Or should we just invest in another line?
Thanks.
Caroline

Any blockage of the pump's water line inlet in the lake (the foot valve screen) will cause this. So will a blocked jet in a single line (shallow well) jet pump. That's inside the wet end where the line from the lake connects-some pumps have a plug just under the connection to clean the jet through. So will a worn imnpellor.

If a blocked jet, you have to shut off the pup and depressurize the system before opening the line or removing any plug.

Gary
Quality Water Associates

Not sure how deep the inlet is, but maybe get a face mask and dive down and check it out. If it is flexible enough, you might just use a boat and pick it up, but you don't want to break or kink the line. Do you have a friend who scuba dives?