Please Help Me Diagnose This Problem

[nhguy261]

Below is my well system equipment and replacement dates. I describe the problem below that.

Well depth ~360 feet
Well age 21 years
Gould submersible pump with 3/4 HP 230 volt motor (10 years old)
40/60 Square D pressure switch (new May 2011)
Pressure gauge (new May 2011)
Check valve at tank (new May 2011)
Check valve in well (original)
20 gallon Utilitech diaphragm tank (new March 2012)
Whole house sediment filter

In May 2011, we started to get low pressure and air in the plumbing so I had the local well company come out to take a look. The service tech said that the low pressure was caused by the clogged sediment filter which I couldn't believe because I'm diligent about replacing it but sure enough, a new filter made all the difference. Regarding the air in the system, he couldn't say with certainty what the source of the air was and offered to pull the pump, replace the in-house parts or both. In the interest of keeping the cost down, I opted to have the in-house parts replaced. He replaced the pressure gauge, check valve and pressure switch and made any necessary adjustments. By the time he left it was running pretty good.

In December 2011, we started to experience 3-4 seconds of low pressure. Thinking the tube between the manifold and the pressure switch was restricted, I took it apart to clean it but there nothing in there to clean. The low pressure continued and I began to suspect the pressure tank but wasn't convinced that the tank was the problem until I noticed that when I drained the tank to check the pressure, the pressure keep increasing even though I had never added air. This happened three times until finally I replaced the tank last month and solved that problem but somehow created the problem I have now.

Immediately after the tank replacement, we started getting air in the system again. Everytime the pump turns on, I can see air in the opaque 90 degree elbows and in the whole house filter. I checked all the clamps and fittings but everything seemed fine. Last week during one of my daily visits to the tank, I found the sediment filter only 2/3 full and couldn't understand what conditions would cause this. Tis weekend I was going to take the well cap off and listen for air being sucked in/out at the pitless or leaking at the pitless. Tonight I went down to the tank and found the filter housing only 2/3 full and I could hear a faint click click noise every 45 seconds, give or take a second. The pressure gauge read about 41-42 psi so I took the opportunity to do an experiment. I made sure the water wasn't used and sure enough, about an hour later, the pressure dropped enough to turn the pump on.

So, what do you think? Is the pump short cycling? Is there a bad check valve? A bad pitless? Should I start making funeral arrangements for the pump?

All suggestions and comments are welcome and appreciated.

Thanks for taking the time to read my post.

 

[Teets]

Bad check valve on the pump, or a leak in the drop pipe sucking air through the pitless adapter.

 

[Sponsor]

 

[Valveman]

Remove the above ground check valve and the air problem will go away. Although the above ground check valve is probably masking the real problem. Removing the above ground check valve will either make the check on the pump start holding or you will continue to see a drop in pressure when not using any water. Most likely you will need to replace the check on the pump, or you have a hole in the drop pipe. Either way you don't want another check valve other than a good one on the pump.