Can you help with our well problem, please?

November 8, 2010 11:43 AM

We seem to be having a problem with our well/water system where water intermittently goes out for a short time (about 30 seconds). I'm not sure what the likely problems are, and would appreciate your help diagnosing the problem so I can (1) repair it, or (2) figure out who to call for a repair. Details/my observations thus far are inside.

So we've lived in our house for about 3 years and never had trouble with our water supply until now. Lately, every other day or so (with varying frequency), our water goes out for about 30 seconds before coming back on.

Our system is somewhat complex, but no worse than average. We have a well (I think it's a bit under 200 feet deep, and when we bought the house, we were told it exceeded 5 gpm, which is pretty good in this area allegedly.) From there, we have a large (bladder tank (I can't recall the size), a filter, and a water softener.

I've attempted to diagnose our problem and made a few observations-

1) The pressure switch appears to be function properly. Currently, the cut-on pressure is ~35 psi and the cut-off pressure is ~50 psi.

2) When the pressure switch kicks on, the pump runs for a little while (30 seconds - a minute, maybe?) and the pressure is going up, then cuts off for a little while (again, maybe 30 seconds to a minute) and so on, duty cycling until the cut-off pressure is reached. I don't THINK this is normal or used to happen.... Is this a thermal protector switch?

3) I've never been able to observe the pressure during the service interruptions, but my guess is that it drops.

So what are the likely problems? Is our pump on its way out? Is our well not producing like it should? Or are these a red herring for a problem further down the stream? Are there other things I should check?

Thanks in advance!

posted by JMOZ to Home & Garden (6 answers total)

It may be that your well is just failing to fill fast enough to keep up with the water flowing out of the taps when you use them. If this is so, then it recovers when the level of water in the well again reaches the intake device. I'm no well expert, but we have well water ourselves.

A well-digger may be able to offer an opinion.
posted by Jenna Brown at 11:47 AM on November 8, 2010

You might want them to check for a leak in the bladder tank - we had this and it causes the pump to cycle a lot, as well as not being able to store much water. The only outside indication we had was a tiny trickle of water from beneath the tank.
posted by rfs at 12:01 PM on November 8, 2010

The classical reason for this is in fact a leak in the bladder tank (or in older type pressure tanks, that the air gets absorbed into the water so that the pre-pressure gets too low). On top of that your pump may be on the way out because of a long period of too much on-and-offing.

I say the latter only because you say the pressure switch works okay, but the pump stalls and re-ingages while it is on. That seems not normal to me. If the diaphragm is gone, the first thing to happen would be that the pressure switch would go on and off a lot, the pump duly following suit.

You need a plumber specialized in freshwater systems. Also you should get a gauge installed that makes that you are able to observe the pressure during the service interruptions.
posted by Namlit at 1:08 PM on November 8, 2010

I don't think this is a bladder problem, since you state that the pump cuts out before you reacg cut-out pressure. I would go with the thought that the pump is over-drawing the well. If you have had one or two dry seasons where you live the water table may have dropped. We had similar problems with a well and ended up lowering the pump twenty feet. This stopped the problem as the water level in the well stayed above the pump intake. You need a well specialist to measure the static water level and the draw-down level when the pump operates. If you have the available depth in the well and no sand problems he may be able to drop the pump a little.

You local health department or similar agency should have a record of the well depth and casing material if there was a drilling permit issued. This is invaluable information to have when deciding how the deal with a well.
posted by Old Geezer at 4:39 PM on November 8, 2010

Namlit- we have a gauge, but the interruptions usually happen when I'm in the shower (or my wife is in the shower) and only last roughly 30 seconds, making it pretty tough to catch them.

I think the plan is to call the well experts rather than the company that installed the bladder tank for the previous owners. The tank is only a few years old, so I'm guessing it's the well or the pump. It might be both, but the symptoms don't seem to match. (The pump doesn't seem to be cycling particularly often as far as I can tell.)

I'll post back when I hear more and keep checking in case anyone has other ideas. Thanks!
posted by JMOZ at 6:02 AM on November 9, 2010

Took a while to get this resolved, but the pump was on its way out. It's now been replaced. Thanks for the thoughts/feedback, all.
posted by JMOZ at 11:25 AM on January 3, 2011