Greetings plumbing experts!

I have a problem I've been struggling with for four years. I bought a house on a well system, with a bladder pressure tank. The pressure has always been poor, and changing the water filters, etc. help marginally when they are really dirty, but regardless of how recently the filters have been changed, when you flush a toilet, the sink next to it is dry until the tank refills, and if you are showering and someone turns on a faucet, the shower goes completely dry. If nothing has been turned on and the well pump has pressurized recently, you get a "burst" of higher pressure from a shower head or faucet for a few seconds before it goes back to a unimpressive flow, but opening more than one tap at a time cuts the pressure to almost nothing. It's a 3 level house and the pressure is definitely better downstairs, which I'm assuming is a combination of perhaps 3/4" pipe rather than 1/2" pipe and less bends in the line.

I had a well guy come out and we determined that there were no leaks in the house system (we shut off the water valve once the well pump brought the system up to pressure, didn't use any water, and it held at pump pressure 30 minutes). We then did the same thing for the pressure tank/bladder system, let the well pump pressurize and then closed valves to isolate the tank, it holds pressure just fine. We then adjusted the tank from a 40/60 range to a 50/70 range (which didn't help at all). I would say with normal usage the well pump is coming on every 10-15 minutes to repressurize. Since we have a pressure gauge on both the well side and the house side of the valve shutoff, we did determine that the well pump was not holding pressure when isolated. But it seems to me that the result of this would be more frequent pump cycles but that the pressure tank should still maintain decent pressure in the house - but this is not the case, the house has decent pressure for maybe 3 seconds from a fresh cycle. Should the well line losing pressure immediately result in lousy house pressure immediately? Why wouldn't the pressure tank keep the house pressure constant for at least a few minutes until the pump needs to run again?

The well is 200 feet, and the pump is quite ancient. The well guy is telling me that since it appears the pump line is not holding water that we either have a bad check valve near the pump, or a pinhole leak somewhere in the shaft - both requiring pulling the pump. The pump was installed in 1979 and actually still works but pulling it to fix a check valve or pinhole leak and then hoping that a 37 year old pump continues to work is a big risk obviously, and I'm not 100% convinced it would fix my low pressure issues anyway, given what I've detailed plus one more odd thing going on with irrigation.

We recently started irrigating the yard. I had fully expected that when the outside irrigation was running, that we would be dry inside the house just like we are when we try to shower and flush a toilet, etc. But that is not the case, the irrigation being on or off has zero impact on water pressure in the house,or maybe even makes it a little better, which is really confusing to me. I have no idea if the pump feeds an outside irrigation line that is isolated from the house (no irrigation shut off valves in the house), but it appears that the irrigation does not run into the pressure tank bladder first. I've never owned a well so don't know if it is standard to put irrigation on a pump without a pressure tank, just like I don't know if 10-15 minute pump cycles are normal (takes about 15 seconds to bring pressure from 50 to 70).

So under that assumption, if there is enough pump power to keep the irrigation going and still allow the house it's regular (but weak) pressure - doesn't that indicate something else is causing my pressure issues other than a well leak?

I guess if turning on the irrigation turns on the pump continuously rather than in cycles like house usage then the pinhole leak or bad check valve might not be as significant as when the pump runs for just the house and then turns off and leaks. Writing this up has me thinking what I need to do is monitor pump activity when irrigation is on to see if the pump runs continuously when the irrigation is on.

Bottom line - when I have multiple gauges that are telling me my house pressure is always between 50 and 70 psi, and a pump that recycles about every 10-15 minutes - seems like I should be able to flush a toilet and not have to wait 60 seconds for water to appear at the faucet next to it to wash hands.

Any ideas? Help is much appreciated!

Dan

It sounds like there is a serious restriction in the piping, maybe a galvanized pipe or fittings near the pressure tank. Or a faulty main cutoff valve near the filter. I believe the pump, pressure tank and switch are all working as they should. You need to figure out where the irrigation system ties in, and look for the restriction ahead of that point.

pretty sure the irrigation ties in somewhere between the pump and the house underground (a big manifold box is buried between the pump and house). But the piping is 1.5-2 inch PVC coming from the well to the pressure tank and then to the two filters, then distributes to 3/4" copper from 1979 mostly downstairs) and clear 1/2" PEX from a major remod in 2012 (mostly upstairs), except for a small galvanized piece coming out of the pressure tank with a gauge on it. But our water has a serious amount of red silt in it creating a need for two filters (bag and cannister) that I change out quarterly. Could there be silt plugs or something in the house lines? I change the filters when I start to see yellow water at the faucets (every 3 months or so).

If the pump is working as it should, why does it lose back pressure quickly even when no water is being used? Maybe I have two problems, a bad check valve and/or pinhole leak, but also a serious restriction somewhere in the house system? My assumption is that a pump line losing back pressure would create frequent cycling, but not the super low pressure - so the idea of a restriction somewhere in the house makes a lot of sense given the irrigation runs just fine. The question is, can a good plumber find the restriction and is it a design flaw or a plugged pipe?

Since the downstairs runs so much better than the upstairs, that might help isolate where the restriction might be - but it wouldn't be at the small galvanized pressure tank piece as that feeds everything.

Hmmm, more to think about for sure, thanks for the idea and I would welcome opinions on whether a good plumber can find and fix something like this if it's not the well system.

thanks
Dan




thanks!

Your pressure is better when the irrigation system is on because the pump now has to run continuously. As NCP states, the problem will be found in your distribution system. The well side leak problem is separate from the house pressure problem.

So two separate issues, I get that now. Any tips for finding/fixing a restriction in the house distribution system? I will check all valves, but the way it acts (restriction on the top two floors but not in the basement), makes me think it is either a mineral plug (there is a ton of red sediment in our water) or a design problem as the top two floors got new plumbing in 2012 (clear pex) but the basement is 1979 copper. No galvanized anywhere but right at the pressure tank, which feeds everything.

You stated that you have 1/2 inch pex supplying your upstairs, having that small diameter
of a line feeding upstairs will limit the amount of water that can be supplied, so your water pressure will drop quickly after turning on your water upstairs.