Water Pressure.....

Specific Inspection Topics Plumbing Inspections
1

Problem: I have significantly reduced water pressure and I am not sure what could be wrong. Before I begin replacing random items (e.g. pressure tank, pump, etc.), can someone please give me some insight into what may be the cause of my drop in pressure?

My home is 35 years old and I have a well with a submerssible pump (unknown depth…less than 200’, unknown hp rating). My water line, from the pump to the house, is 3/4" PVC and I do have a pressurized holding tank. The pump has been replacced at least once, maybe twice during the lifetime of the house. Today (5/3), I drained the water lines, pressure tank, etc. and took a pressure reading of my holding tank (~24 psi) and my pressure switch is a 30/50, so I added about 4lbs of air to my tank to bring it to 2lbs less that the low pressure setting. If I am washing clothes or flush the commode, my pressure drops significantly. I have low pressure while I am taking a shower, without any other water demand. I have lived in this house since it has been built and this has not been a problem until receintly (the last 1-1/2 to 2 years). I live at the bottom of a hill in a neighborhood and I have more than an acre separating my neighbors on each side of me.

Thank you for your help…

2

24 psi is very low. A minimum of 40 psi is more typical.

Do you have a working pressure gauge on the system?
They often go bad and give erroneous readings.

Watch the gauge while the pump is running.
It should pump up to the cut out setting of the pressure switch.

3

You did not mention the presence of a whole house water filter.

If you have one, replace it, if you don’t have one, remove and clean/replace all screens in fixtures.

A good setting for your well pump is 50/65 but this will not work well if you have debris buildup somewhere.

4

Does the water have debris in it - sand, grit, black spots, ??? Catch some and look at it. Check the tank on the toilet for foreign stuff.

5

You also didn’t mention where you live. A lot of the mountain areas here in East San Diego County have water pressures in the 18-30 psi range. It’s just something they have to put up with for the privilege of living out in the moutains where they occasionally have to deal with that white stuff that falls from the sky.

6

Update (5/4): Thanks for the replies. I live in North Carolina (Raleigh) and I don’t have a lot of mineral deposits or sediment in my water, however, I do have a whole hous water filter and it is changed regularly. According to the manufacturers instructions, I am supposed to inflate the bladder to two pounds less than the minimum pressure rating on my pressure switch, whcih didn’t seem to help. Should it be more or less?
Also, could there be a problem with my pump? Could the impeller be disintegrating? I do have sediment, but it is not excessive. I change my filter once every three months regardless. Replacing my pump is a last resort due to the cost and I am not sure if I would need to run a new 1" water line since the old one is 3/4". This is frustrating…

7

Changing to a 1" pipe will not solve the problem, you said it worked ok before.

You need to listen to the pump or monitor the contactor vs pressure (using a new gauge) and see what the real pressure values are at throughout the cycle range. 30/50 is way too low of a setting, set it for 50/65 and see if it gets better. You will need hollow nut driver shafts to fit over the adjustment studs or long deep sockets.

If still bad, It’s either a pinched line or a bad pump.

8

I just thought of something else,

The filter head has an adjustment that goes from filter to off to bypass.

Someone may have turned this and left it halfway between two settings.

If it is in “filter” position, turn it to bypass and see if it gets better, if it does, replace the filter assy.