Well pump check valve faulty?

[Don Key Hotay]

I believe my well pump check valve might be faulty.
The issue is that the plumbing system will slowly lose pressure, such that the pump cycles about every 40 minutes without any water usage in the house. I do have a toilet that has a very minor leaky flush valve which couldn't possibly account for the frequency of the well pump cycling.

My air tank holds proper pressure and does not appear to be taking on water. I also eliminated the possibility of leaks from our outdoor water fixtures, by shutting off all outside plumbing.

So, here goes my question: If the pump cycles and fully pressurizes the system, then I turn off the pump at the breaker, should the plumbing system stay at constant pressure for several hours or indefinitely? If it does not stay pressurized, would the check valve be a likely culprit?

Many thanks for any info you can provide!

 

[sarg]

Likely - Yes.
Do you have a shut-off after the pressure tank such that you can isolate the toilet fill valve from calling for water ?
If you can ... then watch your pressure gauge. If it drops ... it then is a leak between the pressure tank and the pump .... leaking fractured pipe ? pitless adapter ? ... or the check valve ( assumes you have only one check valve at the pump. )

 

[Don Key Hotay]

Thanks very much for the information. I will pursue the leads you suggest and see what happens. Thanks again!

 

[sarg]

Just to note ...... I had the same situation last November when I replaced everything inside the house.. The pump would cycle every 35-45 minutes because the check valve on our 29 year old Franklin submersible wore out. The pump functioned fine but the valve would not hold.
Spent the $1700 to replace it before the really cold weather set in ... just to be safe.

 

[Don Key Hotay]

Good to know. I need to dig out the documents to see when the previous owner installed this pump. Thank you.

 

[Valveman]

It could also be a hole in the drop pipe. However, it is most likely a faulty check valve as those are destroyed from the pump cycling on and off too much. Cycling causes the check valve to be thrown open forcefully and slam shut over and over which destroys the check valve as well as many other things.

 

[RS]

Hopefully you have a shutoff like sarge suggested, so you can completely isolate the system. When we had this same problem it was a cracked fitting just outside the casing, the adapter that screwed into the pitless adapter. A friend had had the same problem earlier, so I knew it was a possibility. I took the cover off the well and listened carefully, I could hear a hissing sound. Now if you hear the same thing it could also be a hole in the drop pipe, as Valveman suggested. They used to use galvanized pipe to hang the pump and it would rust through in the threads just above the pump. I dug down by hand over 7 feet and fixed mine, cost me about $5!

 

[Don Key Hotay]

Hopefully you have a shutoff like sarge suggested, so you can completely isolate the system. When we had this same problem it was a cracked fitting just outside the casing, the adapter that screwed into the pitless adapter. A friend had had the same problem earlier, so I knew it was a possibility. I took the cover off the well and listened carefully, I could hear a hissing sound. Now if you hear the same thing it could also be a hole in the drop pipe, as Valveman suggested. They used to use galvanized pipe to hang the pump and it would rust through in the threads just above the pump. I dug down by hand over 7 feet and fixed mine, cost me about $5!

Excellent suggestion. I will listen for the hiss. Thanks!