Over the past two weeks I've noticed our submersible well pump seemed to be short cycling. I figured the Well X Trol tank was water logged. This morning I isolated it and drained the water from it. Didn't seem to me that enough water came out (2 or 3 gallons maybe) but it was empty. Checked the air precharge pressure which was 27#. The cut-in is set at 35# and cut out at 60 so I increased the air precharge to 33# and lined it back up. It seemed to be worse so I repeated the process except that I removed the schrader valve and bled the air pressure to zero. Didn't get any moisture from the air side of the bladder when I vented it. I'm thinking there would be water on the air side of the bladder if it had failed. The water pressure drops when a valve is opened, the pumps starts (most times!) when system pressure hits 35#, the pump cuts out at 60# and when it does the pressure guage drops back to 40# immediately. A couple of times since I started messing with it, the system pressure dropped to zero and the pump doesn't start. Anybody got any advice? I suppose there ain't a lot of moving parts here. The pumps pumpin', the pressure switch is kinda workin' so it's pretty much gotta be the pressure tank huh. Thanks.

 

I would bet the problem is a blockage in the elbow on the bottom of the pressure tank. Also it sounds like the pressure switch is partially plugged if it occasionally doesn't turn the pump on until the pressure drops to zero. It is VERY likely that IF the switch is plugged (the nipple/hose to the switch or the switch itself) then the tank elbow is severely blocked and is causing the problem.

The reason it happens is because - using round numbers for explanation purposes - the pump is bringing in 10 GPM (gallons per minute) and the blockage at the tank elbow is only letting 5 GPM into the tank. The pump will build 60 PSI on the line feeding the tank and the pressure switch but because of the flow restriction entering the tank it cannot get that same pressure into the tank. Eventually the line pressure will reach the cut-out pressure of the switch but because the tank did not fill (due to the blockage) the actual pressure in the tank is lower so the line pressure will ALWAYS even back out to the tank pressure once the pump shuts off.

I have been in the well water business for 16+ years and have only see the problem you're describing happen when the tank elbow was blocked OR the "air side" of the tank had been breached allowing water on that side. If it is water on the air side causing problems then simply removing the schrader valve won't always tell you it's there. You may have to physically shake the tank once it reads zero pressure on the gauge to see if you can hear water moving inside of it or to see if it feels like water is sloshing around in the tank. The weight of the tank would also be an indicator but you would need to know what it feels like empty to be able to accurately compare.

 

Thanks Shane, you're right. I stopped and picked up both a new pressure switch and new Well-X-Trol this morning. Rationally I couldn't see that there would be a problem on the air side of the tank but we have an iron problem in this part of NH so I thought the switch might be plugged internally. Removed the switch and there was no visable pluggage. Replaced it and started the pump. Same result short cycling and only a few gallons of water in the tank. I removed the tank and when I took the Tee off the bottom it was plugged except for a 1/4" hole. The elbow at the base of the tank was also plugged. Cleaned out the Tee and replaced the tank and we're back in business. Thanks for your help.

 

no prob glad I could help.