Well pump pressure loss

Question

We have owned the house for 5 years and not had any water pressure issues.

The pressure gauge on the pipe to the pressure tank has been rusted since we bought the house. The pressure tank is blue and roughly 4 ft tall. The pressure gauge reads 24 psi. The label on the pressure tank states that it has been pre-charged for 30 psi. The pressure gauge reading does not change at all when we turn on faucets, flush toilets or run the washing machine. Am I correct in guessing that the pressure gauge is stuck or broken and needs to be replaced?

What should a typical pressure gauge reading be? And how much should it go up and down upon water usage. What factors affect pressure gauge reading? The pump goes on and off as expected when faucets are turned on and off.

The water pressure is pretty good except when we flush 2 toilets at the same time and turn on a faucet when the toilet reservoirs are refilling, the faucet pressure is very low. This drop in water pressure has just recently presented itself. How do I determine how much water draw is supported by the well & pump?

I don't seem to have any documentation on the well & pump. Is this something that is filed with the town? Where could I get a record of this?

Thanks, V.

Answer 1

The Pressure gauge reading cycles between the pump cut-in and cut-out pressures. Sounds like the gauge is dead and permanently stuck at 24psi.

Often, the cut-in and cut-out pressures will be listed on the pressure switch and commonly are 20psi cut-in and 40psi cut-out. So your water pressure on the gauge will cycle between 20 and 40psi during water usage.

The tank has a built-in bladder that is pre-charged to 30psi when your gauge reading is 0psi (pump breaker turned off, water tank drained). There should be a faucet somewhere on the pump manifold system that allows you to drain the pressure tank of water so you can check the bladder air pressure.

To repair the gauge, I would switch the power to the pump off, drain the tank and simultaneously, replace the gauge and check the bladder pressure and top it off if needed. Then power the pump back up.

If there is a lever on the side of the pressure switch (image below), it is a low pressure cutout to prevent the pump from operating if the well runs dry. Pull it up till the pump turns on and hold till the pump stays on (about 10-15psi). With no low pressure cutout, just power the pump on and it will automatically do the rest.

Once you have a working gauge, you can start to determine whether it is a pump pressure supply issue, or if you have something more serious like a restriction in the house supply line or a leak.

Do you have any sort of sedimentation filter in your water system? Sounds like it may have clogged and if a screen, needs flushed or replaced if it's one of those string filters.