Well pressure tank won't rebuild pressure with water running and loses some when its not

[Matt Hacket]

So as the title says, my well pressure tank will not build pressure back while water is running in the house. The tank starts with full pressure (60psi) when a faucet is opened and drops normally while running down to 40psi and the switch kicks the pump on. It sits at 40psi for a few minutes and then starts to drop further down to around 30psi (sometimes lower) and never builds back up with the water still running. It will build back up once the water is turned off but when it sits for a while it will sometimes start to lose pressure. Not enough to make the switch kick on the pump but usually between 10 and 15 psi. If I turn the valve to cut off the water to the house it will keep the pressure. There is no check valve that I can find above ground in my utility room. The pipe goes down into the slab from inside the house.


Its a submersible pump. 51 feet deep. 4 inch steel casing. Using a well worker 44 gal ht44b. With a 40/60 switch.

Some background info.
I just replaced the pressure tank which was only 2 years but was short cycling and turned out to be waterlogged ( also well worker 44 gal ht44b). I'm guessing this stemmed from the sediment filter not getting changed but I'm not really sure. The filter is after the tank and before the water softner. I bought the house last year and didn't know the filter needed to be changed so often (I've never had a well before).

I changed the tank, the T, the gauge and the switch. It worked fine for a week or so and then noticed the pressure would get lower when running the water for a few minutes. Went and watched what the gauge to see what it was doing and observed what I reported above. I thought maybe the switch was was the problem so I went and bought a new one and changed it. Obviously this wasn't the problem. I've searched the forums and used search engines to try and figure this out and so far have come up with very little. Hope I've given enough info that someone can help me figure this out.

Thanks

 

[Reach4]

. It will build back up once the water is turned off but when it sits for a while it will sometimes start to lose pressure. Not enough to make the switch kick on the pump but usually between 10 and 15 psi.

I am not sure what you are saying there. The pressure on the pressure gauge can fall to 15 psi without the pressure switch turning the pump on? Could you be saying that?

If I turn the valve to cut off the water to the house it will keep the pressure.

That implies a leak or water usage of some sort in the house (downstream of the valve). But this may only happen part of the time, because you did not say that dropping was always the case. So maybe you have something like a reverse osmosis unit that draws water, or something else that uses water.

I just replaced the pressure tank which was only 2 years but was short cycling and turned out to be waterlogged ( also well worker 44 gal ht44b). I'm guessing this stemmed from the sediment filter not getting changed but I'm not really sure. The filter is after the tank and before the water softener.

The filter is also after the pressure gauge, and the pressure switch and pressure gauge are near each other, and they are also near the input to the pressure tank. I assume those are the case, but just checking for confirmation.

Failing pump seems most likely to me. Two-wire pump (no control box)?

If you change pumps, with a 4 inch steel casing, here are your better choices:
1. Slimline/trimline "4-inch" pump
2. 3-inch SQ pump with no flow inducer
3. 3-inch SQ pump with flow inducer

Is your 4 inch well out in the yard? Do you have a pit?

 

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[Matt Hacket]

I am not sure what you are saying there. The pressure on the pressure gauge can fall to 15 psi without the pressure switch turning the pump on? Could you be saying that?

No the pressure will drop from 60psi down to 50psi or less when water is not being used. This didnt happen before I changed the tank and other parts. I only know this because when trying to troubleshoot the short cycling I was watching the gauge a pretty fair amount.

That implies a leak or water usage of some sort in the house (downstream of the valve). But this may only happen part of the time, because you did not say that dropping was always the case. So maybe you have something like a reverse osmosis unit that draws water, or something else that uses water.

I do have an RO system. But again I didn't notice this happening before changing the tank. I mentioned that it held pressure with the valve to the house closed and that I couldn't find a check valve mainly to potentially rule out the thought of water flowing back down into the well.

The filter is also after the pressure gauge, and the pressure switch and pressure gauge are near each other, and they are also near the input to the pressure tank. I assume those are the case, but just checking for confirmation.

Yes. The switch and gauge are on the T pipe of the pressure tank.

Failing pump seems most likely to me. Two-wire pump (no control box)?

Had to look it up what it was to make sure. No control box.

If you change pumps, with a 4 inch steel casing, here are your better choices:
1. Slimline/trimline "4-inch" pump
2. 3-inch SQ pump with no flow inducer
3. 3-inch SQ pump with flow inducer

Is your 4 inch well out in the yard? Do you have a pit?

Yes it is about 10 feet behind my house. Not sure what a "pit" is.

 

[Reach4]

Yes it is about 10 feet behind my house. Not sure what a "pit" is.

How far above ground does your casing extend? Or is the top of the casing below ground level?

How about a photo of what you can see there.

 

[Matt Hacket]

Man I sure messed up pulling quotes to answer each different question. I'll have to work on that.

 

[Matt Hacket]

Its about 12 inches above the ground

 

[Reach4]

Man I sure messed up pulling quotes to answer each different question. I'll have to work on that.

You can usually drag-select a string, and click reply.

Your well cap looks like mine from up top. You might lift the lid after loosening 3 bolts, and show a picture. See https://terrylove.com/forums/index.php?threads/how-to-pull-unusual-well.62697/ to compare to what you see.

I have a Merrill SMCK-4 pitless on my 4-inch steel casing. I had my pit demolished, casing extended by welding, and pitless installed. You may have had a pit once upon a time, but yours got filled in with concrete blocks after the casing was extended.

A 5-gpm Grundfos SQ pump would handle most houses, unless you have a high gpm need. The 5 gpm pump puts out about 7 gpm typically. So if you might go that way, we can discuss flow inducer sleeves.

 

[Matt Hacket]

I'll go grab some photos with the top off shortly here when the snow let's up. The cinder blocks are actually surrounding the well head because a raised flower bed was built around it.

I had the well inspected before buying the house and they said it was pushing 11GPM. Dont know if thats more than what I really need when considering a new pump. But I do have a a lot of gardens that get watered in the summer.

So would there be anything else I should check before replacing the pump?

 

[Reach4]

So would there be anything else I should check before replacing the pump?

You could address the question in #2. I am trying to understand your symptoms.

 

[Matt Hacket]

Perhaps I did in my first reply to you? The one that showed up all orange. Looks like I responded to everything you asked. If I missed it let me know and I will.

Sorry, I've never posted in a forum before. Usually I can search and find my issue by reading them or on you tube.

Thanks for taking the time to help.

 

[Reach4]

It will build back up once the water is turned off but when it sits for a while it will sometimes start to lose pressure. Not enough to make the switch kick on the pump but usually between 10 and 15 psi.

So you are saying the pressure might drop from 60 down to 50 or 45. The RO drawing water could explain that, as it refills the RO tank. For every gallon of RO water used, over 5 gallons of water may be drawn.

I would be thinking Grundfos 5SQ05-180 or 10SQ05-160. Those are two-wire pumps, and are available in both 115 volt and 230 volt. Others may have a different idea.

The 5SQ has a 1 inch NPT connection, and the 10SQ has 1.25 inch NTP, which you might reduce down to 1 inch.

 

[Matt Hacket]

Got the cap off. Cracked it on the edge either because its old or because its cold or both. But I guess I'll replace that now too. I van take better photos in the morning if need be.

 

[Reach4]

I would use a vacuum cleaner as I tried to scrape off the stuff. I don't know how that crud got in there.

Looks similar to, but not the same as, the kind of pitless that I have. I suspect that arrow points to the direction that the pipe connects to.

Try reading up on MCK, SMCK, and other similar pitless adapters.

My well cap may be Campbell SC-4 https://www.envisupply.com/pdf/campbell_catalog.pdf
I am not sure on mine, and certainly not sure on yours.

Your well cap has an info plate. I would contact them.

 

[Matt Hacket]

So is there anything else I can answer for the purposes of continuing a diagnosis? Or should I start to lean toward the pump? From everything I read before joining here to ask, I was thinking it may be the pump. But given my lack of experience with wells I wanted to be sure I wasn't missing something.

 

[Valveman]

If it only leaks down when the valve to the house is open, there is a leak or a demand in the house. Try running a big valve or several faucets open and see if you can get 11 GPM and for how long. I am thinking you may also have a leak below the check valve in the well, like at the pump. Check with a clip around AC amp meter while the pump is running. Full amps means you have a hole down the well. Low amps would mean the pump is worn or the pump screen is clogged.

 

[Reach4]

If it only leaks down when the valve to the house is open, there is a leak or a demand in the house.

There is an RO unit, so I think that could explain the demand that is sometimes there.

I am thinking you may also have a leak below the check valve in the well, like at the pump. Check with a clip around AC amp meter while the pump is running. Full amps means you have a hole down the well. Low amps would mean the pump is worn or the pump screen is clogged.

I wonder if we can presume a 1/2 HP pump motor.
If so, and if the pump is powered through a 2-pole breaker, then high amps would be 5 or more?

 

[LLigetfa]

It sits at 40psi for a few minutes and then starts to drop further down to around 30psi (sometimes lower) and never builds back up with the water still running.

To put things into context, it would be good to know how many GPM is being drawn for the pump to not be able to keep up. Assuming you have a tank drain before the main shut-off, shut off the water to the house and vary the draw of water from the tank drain, measuring the GPM you can draw for the pressure to hold at 40 PSI. That will show how many GPM the pump produces at 40 PSI.

 

[Matt Hacket]

Thanks guys i will check these things as soon as I can.

 

[LLigetfa]

vary the draw of water from the tank drain, measuring the GPM you can draw for the pressure to hold at 40 PSI. That will show how many GPM the pump produces at 40 PSI.

Do note that the GPM the pump can produce will depend on the water level in the well. As the level gets drawn down, the pump will produce less GPM.

 

[Matt Hacket]

So I got around to doing a few more tests (I've been ill the last few days). I checked the GPM from the tub which is normally the fastest running faucet and was getting around 4.5 GPM. I started with a full tank and 60 psi and got around 9 gallons in 2 minutes and once the pressure dropped to under 40 psi and the pump kicked on it went down to about 3 GPM. I then tried opening more than one faucet as suggested but it didn't change the GPM (still around 4.5).

It is a 2 pole breaker. I checked the amps (hopefully correctly, see photo) and got 2.7 amps while the pump was running.