Backup well/pressure switch problem?

We have 2 wells (handy in Western PA mine country). We use the backup well (used to be the primary well with original owner) to occasionally supplement horse trough water when the troughs need to be cleaned or when the primary well has a dry head condition.

On the backup well, we have a new pump (1 yr old), a new pressure switch (30-50) and a new pressure gauge. The State Pumpmate tank air pressure is adjusted to 28 lbs. The PS, PT and PG are in a cinderblock pit outdoors. I mention that the pressure switch is brand new and the contacts have not yet corroded due to humid conditions in the pit.

The problem is that when I wait some time (3 days or more) to use this well, the pressure has dropped to nothing and I have to use the low pressure lever on the pressure switch. If I then let the tank cycle several times on it's own, no problem. However, the next time I go to use it (several days or weeks later), it again has dropped to nothing.

The only thing I can think of is that maybe the check valve is bad (it is probably 25 - 30 yrs old) but even so, when the pressure drops, why doesn't the pump cycle on it's own? Can the pressure drop so slowly so the pressure switch doesn't recognize the drop? Do I need to move the pressure tank, switch etc into the house? Any help would be appreciated.

I could explain the not coming on part if it were a permanent type of problem, but why it works great while your standing there is a mystery.

You might try cleaning the tubing feeding the pressure switch, it could be closing up with minerals.

bob...

Bob,

Thanks for the quick reply. I replaced the 6" long nipple at the same time as the pressure switch (last week) so hopefully it is something else. Also, the problem was occuring before I replaced the switch as well as after.

Steve

If you have a check valve above ground, it will be holding the pressure in the tank. Then the check valve down on the pump could be leaking back. If there is a schrader valve on the above ground check valve, or a small leak in the pipe, all the pipe in the well will drain back. So when the pressure switch drops to 30 and starts the pump, the air in the drop pipe takes a few seconds to be replaced with water. During these few seconds your pressure switch could drop out on low pressure, and shut the pump off. Removing the above ground check valve could help you find the problem.

Is it possible someone is using this well unknowingly and running it long enough for the low pressure cut off switch to kick in?

bob...

Valveman,
I'll talk to someone about removing/replacing my above ground check valve and let you know how it works out.

Bob,
The only way someone else could be using this well is if a neighbor's well (maybe 100 yds away albeit deeper) is draining my well.

Thank you both,
Steve