Pressure loss in water system

[Mike56]

Here is the problem and background: well is 80', pump at 60', static water at 40, excellent flow and water quality, no history of sand or sediment issues. well age 40 years.. Weeks ago I started seeing a very slow pressure loss, 60 to 40 over about 40 minutes. Isolated it to piping between the house and the pump. Figured a check valve in the well was bleeding down. Well company pulled the pump. Pump was 40 years old, had them install a new one. Drop pipe was 1" threaded, all looked good. They replaced the couplings with SS ones as the originals were galvanized. Used no sealing compound on the threads but did use some type of teflon thread lube. Replaced the check valve at the top of the pipe riser. Some slight debris in the old one but it still looked to be OK and functioning. Pitless adaptor looked good, O-ring looked in like new condition. Flushed the line from pump to pitless. Put it back together, everything good. No more leak down. Three weeks later the issue is back. I'm having a hard time believing the line from the house has a problem. A leak is a leak, it should have still been there after the work was done. Could there be an issue with one of the drop pipes being cracked, possibly at the threads? I'm unsure of what to do or tell the well company to do. Any ideas on what could be going on? Thanks!

 

[Reach4]

Replaced the check valve at the top of the pipe riser. Some slight debris in the old one but it still looked to be OK and functioning. Pitless adapter looked good, O-ring looked in like new condition.

1. You should not have a check valve at the top of the drop pipe.
2. With a bright flashlight at night, look for signs of leakage at the pitless o-ring. It is usually recommended to replace the o-ring when pulling a pitless.

Was o-ring rubber or leather? Is your pitless adapter like one of these?

From https://www.inniswelldrilling.com/the-pitless-adapter/

Take pictures of your pitless the next time it is out.

 

[Sponsor]

 

[Mike56]

Yes, that is the pitless I have. O-ring is rubber. Prior to the pump being pulled, I dropped a camera down to the pitless (5') and could not see any water leakage. I also listened for any sounds of water spraying, nothing. (advice I saw on this forum). May I ask why there should not be a check valve at the top? Just another potential trouble spot and not needed.? So the check valve on the pump is sufficient? The line run into the house is about 75'.

 

[Reach4]

https://terrylove.com/forums/index.php?threads/submersible-pumps-and-multiple-check-valves.26301/ is one of the threads that address this.

How often is your pump cycling when you are not using water?

Did you re-check that this cycling occurs even when the stop valve after the pressure tank is closed?

When you close that valve, I expect a brief burst of water when you open a faucet. If no burst, maybe there is a small leak/water use after the valve. If you close that faucet, and reopen hours later, is there a new burst? It seems to me that a new burst would imply that your stop valve leaks some, and the water use could be something like your humidifier kicking in or a toilet fill valve passing water.

 

[Mike56]

With no water use the pressure bleeds down and the pump kicks in at about 40 minutes after pump shut off at 60psi..
I only checked with the main line incoming shut off. When I do this, the pressure holds fine. I'll check at the shut off just down line of the PT.
I also had the same thought about water burst sound (like air in the line) if there's a leak. But nothing. I open the valve with pump off and 40 psi and nothing. No sound of water movement. It doesn't make sense.

No humidifier and I've checked the toilets. All good.
Also, I will check tonight using the flashlight.

 

[Mike56]

Reach6, Your comment about the inrush sound has me thinking. When the pump was pulled, there was water right up to the check valve. They watched it for a few minutes and no water loss.. I just did a quick calculation off pipe size and the PT output and there should be something around 5 gallons leaking out and that's 125' of 1" pipe. Dang near the entire run. If there's a leak in the well to house pipe, it would have to be right at the point incoming to the house. otherwise the entire pipe would be emptying and there would be a bunch of air incoming, and there's none. I'll be looking at that right now.

 

[Fitter30]

Have 1" galvanize pipe 124' in the water. Well was14 years old. Had several lenghts split at the seam till water pressure dropped. Found out that there was a second check in my crawl space so it didn't show up till it got bad enough.

 

[Fitter30]

Reach6, Your comment about the inrush sound has me thinking. When the pump was pulled, there was water right up to the check valve. They watched it for a few minutes and no water loss.. I just did a quick calculation off pipe size and the PT output and there should be something around 5 gallons leaking out and that's 125' of 1" pipe. Dang near the entire run. If there's a leak in the well to house pipe, it would have to be right at the point incoming to the house. otherwise the entire pipe would be emptying and there would be a bunch of air incoming, and there's none. I'll be looking at that right now.

125' = 54 lbs
Look at post 7 never had any air problems.

 

[Mike56]

125' = 54 lbs
Look at post 7 never had any air problems.

Thank you, good to know.

 

[Reach4]

I only checked with the main line incoming shut off. When I do this, the pressure holds fine. I'll check at the shut off just down line of the PT.

There should not be a stop valve before the pressure tank. Do you have such a valve?

 

[Mike56]

By stop valve do you mean a check valve or a shut off? There is a check valve at the top of the well riser pipe, just before the pitless adaptor. There is a shut off valve where the pipe enters the house just before the PT.

 

[Reach4]

By stop valve do you mean a check valve or a shut off?

Talking about a shut off that stops the water.

You are not supposed to have a shut off (stop) valve between the pump and the pressure switch, because if somebody closes that valve, the pump will use electricity and burn out. Take steps to make sure that valve never gets fully closed. I was actually thinking you might be talking about two other valves. There actually is a time where such a valve, in the path from the pump, makes sense, but only to throttle the flow. Rare conditions. You have to make sure that whoever gets access does not fully close the valve.

Regarding the extra check valve, often it does not cause a problem. I am not saying that it is contributing to this problem. But it can cause or aggravate a problem. One thing about this placement, at least it won't cause a vacuum in the underground piping, as placement at the pressure tank could on occasion.

 

[Mike56]

Understood on the shut off valve. I'll remove the handle so it can't be accidentally closed.
My well guy wants me to replace the PT as he's seen cases where pin hole leaks bleed pressure but don't waterlog the tank. I have a new one to install so will be doing that this PM. Thanks for all your input, Reach.

 

[Bannerman]

If you are keeping the supply shut off valve, suggest installing a pressure relieve valve on the pump side of the valve. Even if the valve becomes closed and deadheads the pump, the PRV will open to relieve excess pressure, which will allow the pump to remain cooled to prevent burning it out.

Multiple check valves often result in water hammer, pipe leaks and other issues. There rightly should be only one check valve in the system, that is, the one located directly within the submersible pump. If for redundancy, you want to use a 2nd check valve, an additional spring loaded CV maybe installed directly at the pump's outlet connection.

As you are planning to replace your pressure tank, consider upgrading your system with a Cycle Stop Valve. The CSV PK1A Pside-Kick kit, includes a CSV, pressure tank, pressure switch, pressure gauge, PRV, fittings and wall brackets.

PK1A kit

If using a CSV, you will not be able to use a PRV on the line between the pump and CSV. Since installing a CSV will require some plumbing modifications, simply remove the supply shut off valve at that time.

 

[Mike56]

Thanks, Bannerman. I do have a CSV installed. Works great, fantastic product. The PT was replaced and it was most of the problem, but not all. My well guys speculation about a pinhole leak in the bladder appears correct. Though I don't understand why the pressure loss showed with the main shut off open, but not when it was closed. Prior, the system was leaking down 20 psi in 40 minutes. Now it is leaking down 20 psi in 2 hours. Next week the well guy is coming out. I've told him to remove the check valve, install all new pipe and couplings, use thread sealant, and replace the PA rubber O-ring as Reach suggested. I'm covering every possible base. I'll make a report back after the work. Thanks for all the help everyone.

 

[Reach4]

Understood on the shut off valve. I'll remove the handle so it can't be accidentally closed.

I guess this was a case where having that valve was handy for diagnosis.

 

[Mike56]

An update: All new drop pipe was installed, check valve removed, CSV rebuilt. Continued to have pressure loss that increased to 20 psi in 15 minutes. A cracked PVC fitting was found at the PA. That was repaired and thought all was good, but no. Still have a pressure loss, still 20 psi in 15 minutes. Hard to believe there were two leaks but apparently so. Here's my next question: Prior to the cracked fitting repair, I would shut off the valve at night isolating the pump from the house. Upon opening the valve in the morning, lots of water from the PT flowing back down the pipe, pump turns on and lots of air incoming, indicating a leak near the well, which is why the digging started at the well. Now, closing the valve at night, opening in the morning, zero movement from the PT, no sounds of water or air. Pressure loss then resumes though. Any idea what this indicates? The pipe from the well to the house is 130 feet underground, the last 30' being under slab. I'm currently working on routing a new pipe (Pex A) to bypass the under slab section and reconnect to the PVC before it enters the house. Trying to isolate which section is leaking.

 

[Reach4]

A cracked PVC fitting was found at the PA.

I have figured out that PA is your abbreviation for pitless adapter. That took a minute. I guessed PT right away.

Threaded fitting? Female fitting?

When running plastic pipe, you need to allow for thermal expansion. When running your PEX, don't pull the pipe tight, but instead snake it in the trench.

 

[Mike56]

I have figured out that PA is your abbreviation for pitless adapter. That took a minute. I guessed PT right away.

Threaded fitting? Female fitting?

When running plastic pipe, you need to allow for thermal expansion. When running your PEX, don't pull the pipe tight, but instead snake it in the trench.

Thanks for the Pex tip.