Low water flow/pressure when using two or more faucets/appliances on well

[NurseJeff]

I live in a house that has a well. I do not know the specifics of the well as to depth, width or the type of pump other than it is submersible. The well is in the basement of the house and easy to access.
The pressure and flow are fine when taking a shower without anything else running or washing hands at the sink. The problem exists when flushing the toilet and then washing hands right after and the water flow from the sink is cut in half or less, and as soon as the toilet tank finishes filling up the sink pressure/flow shoots back up to normal. Happens when any two or more appliances/faucets are being used such as toilet flush and shower has low flow until toilet finishes filling or washer is running and all the faucets will have really low flow, but all of them operate normal with normal pressure and flow when being used by themselves. I bought a pressure gauge and threaded it on to the clothes washers cold water valve and opened it up and reads 55 psi, then turn on water at utility sink a few feet away and the gauge drops to around 20psi on the washers line. This happens all over the house, doesnt matter which two appliances it is or where they are located, it always happens when two or more things are being used, though the toilet filling with sink faucets seems to be the worst (lowest flow)

The plumbing goes from the well head to pressure tank via 1" pex, the pressure tank is 6 months old and is not the issue because the issue was around before replacing the pressure tank, pressure switch is set to 40-60 reduces to 3/4" pipe after pressure tank then goes into a AIO filter (Fleck 2510 sxt), then to a water softener (Fleck 5600 ecominder) and then through a 10"x2" sediment filter.

I have tried removing the sediment filter and put the AIO and water softener filters on bypass and the problem gets better but only slightly so I dont think any of the filters are the issue. All the shut offs are fully open. I dont know if this is related or not, but also when using the hose outside I have a ton of good pressure for a few seconds then dies off a little. It doesnt die off to a bad flow but not as good as the first few seconds.


Anything help to figure this out or help would be appreciated

 

[Reach4]

I bought a pressure gauge and threaded it on to the clothes washers cold water valve and opened it up and reads 55 psi, then turn on water at utility sink a few feet away and the gauge drops to around 20psi on the washers line.

Is this the case, even before the pump turns on?

What does the pressure gauge at the pressure switch show during this?

Try putting your new pressure gauge on the drain valve at the pressure tank if you have any doubt about the pressure gauge at the pressure switch.

 

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[Jadnashua]

What you're describing is a distribution volume problem. This is usually the result of a poorly designed system OR, a degraded, system that could easily just be one galvanized piece of pipe that is restricting the flow. Older galvanized piping or fittings can close off to almost nothing insides before they start to leak once it reaches the outside.

Pressure has a couple of ways to express itself...static pressure is what you have when there's no flow. That, except for elevation changes, should be the same everywhere. Then, there's dynamic pressure, and that's based on frictional losses which can be because of long distances, too small pipes, or a newly created restriction...in a pumped system, especially an older one, they may have used some galvanized fittings. Over time, those start to rust out from the inside, and rust, being larger than elemental iron, and rougher, start to make the ID of the pipe quite small, and create much more friction, and the system loses the ability to flow larger volumes of water.

So, take a look around, and check any galvanized pipe, and consider changing it out for either copper or something in plastic.

 

[NurseJeff]

Is this the case, even before the pump turns on?

What does the pressure gauge at the pressure switch show during this?

Try putting your new pressure gauge on the drain valve at the pressure tank if you have any doubt about the pressure gauge at the pressure switch.

Yes, this happens regardless of pump being on or not. Where the water supply is not being used at all and someone goes to the bathroom, flushes and goes to wash hands and the water flow from the sink is usable , but far from normal and all this will happen without the pump even turning on yet.

I threaded the pressure gauge onto the pressure tank drain valve and the readings between this and the pressure switch gauge are the same static pressure and visibly the same while running water and decline is unison. Both gauges have no abnormal movement while flushing the toilet and having the bathroom tap open other than a very slow drop and steady decline as what would be considered normal as the pressure tank is emptying before the pump kicks on, but is is very slow and assuming the culprit is after the pressure tank and nothing like when I have the pressure gauge threaded on the outdoor spigot or on the washer cold water valve

I feel it's relevant to also include that we bought the house about 8 months ago and has always had this problem. Of course, we didn't notice the problem right away. We had a well inspection and they rated it at 4GPM and no notation of any problems. All plumbing from well head to pressure tank to water softener is new. The pressure tank developed a leak at a seam a few months after moving in and I replaced it right away with all new plumbing and new pressure tank. Replaced due to the leak and also hoping it would solve the problem as well. the only part I didn't replace is the pressure switch and nipple, I re-used them as they seemed to be working fine.

 

[NurseJeff]

What you're describing is a distribution volume problem. This is usually the result of a poorly designed system OR, a degraded, system that could easily just be one galvanized piece of pipe that is restricting the flow. Older galvanized piping or fittings can close off to almost nothing insides before they start to leak once it reaches the outside.

Pressure has a couple of ways to express itself...static pressure is what you have when there's no flow. That, except for elevation changes, should be the same everywhere. Then, there's dynamic pressure, and that's based on frictional losses which can be because of long distances, too small pipes, or a newly created restriction...in a pumped system, especially an older one, they may have used some galvanized fittings. Over time, those start to rust out from the inside, and rust, being larger than elemental iron, and rougher, start to make the ID of the pipe quite small, and create much more friction, and the system loses the ability to flow larger volumes of water.

So, take a look around, and check any galvanized pipe, and consider changing it out for either copper or something in plastic.

I have searched and I don't see anything that looks like galvanized piping. It all appears to be copper although, some of it looks pretty old. There are some unions near the hot water tank that are quite large, but I have no idea what they are made of. There are some old shut offs that have corrosion that go to second bathroom and I had planned on replacing them, but problem still happens on pipes that are not connected to the pipes that have the corroded shut offs going to the first bathroom. The first bathroom and second bathroom have two different branches. I don't know if this still could be a problem or not since they are all "technically" connected. I have thought about just replumbing the whole house, being a ranch, it is totally doable to do in a few days, but figured Id see if I could solve the issue and save some money since there are no leaks anywhere. I did check out the distribution to make sure something wasn't all wonky with pipe sizes and it seemed to be OK. The only odd thing I found that seems OK but odd is the second bathroom has a 1/2" pipe that runs the whole length of the house just to go to the toilet and the rest of that bathroom (sink and shower) have a different line that branches off from somewhere else after the hot water tank. I thought maybe this could have something to do with it since the toilet branches so earlier, but then I also found that the sink flow is low flushing the other toilet as well and doesnt seem to be localized to any one location. Just when two or more things are using water

 

[Reach4]

and assuming the culprit is after the pressure tank and nothing like when I have the pressure gauge threaded on the outdoor spigot or on the washer cold water valve

Yes. Something is in the way.

How does the pressure on the nearest outside hose bib behave when you use bathroom water? Does it behave like the pressure gauge on the pressure tank (good), or does it drop way down when you use house water? I know the pressure dies down when you use the hose, but what if you are just looking at the pressure gauge? I suspect that goes down too when you use the bathroom water.

You have an obstruction, such as

• a valve partially closed or defective.
• a cartridge filter that is clogged
• a bent/crushed pipe.
• problem in the AIO path
• problem in the softener path.

Do you have flex lines to the AIO or softener?

So to recap, pressure is good at the pressure tank. It is bad before the path before the pipe to the water heater splits off. So the problem is between those two things.

Maybe you should add a boiler drain valve midway in that path. That can mount the pressure gauge.

 

[Valveman]

As was said, If the gauge at the tank shows good pressure but the gauge on the faucet does not, there is an obstruction between the two gauges.