Thursday, January 5, 2012

When A Well Pump Dies - Part I

Apparently our well pump stopped working a few weeks back.  It takes a while to notice this, though, at least for us.  I have to note the water level in the storage tank dropping.  Also, in this case, and elevated PG&E bill was a giveaway too, though I didn't know that at the time it arrived.

I called our preferred well guy and had him do some diagnosis.  I had already verified that we had power getting to the top of the well and that the pump should have been running, but no water was coming out.  He was able to duplicate my results and noted that the current flowing in the wires meant the pump was probably running.  He bypassed the pump controller and the problem continued, so whatever the issue was it was in the well pump, 380 feet below ground.  Oh joy.

Today he came back with his truck to pull the pump and find out what was going on.  These pictures document that little voyage of discovery.

First, here's what the well head looked like before things got started:

The line on the right (with the gray box) is the electrical supply that drives the pump.  The line in the middle going into the ground is the water discharge.  That goes off to our storage tanks.  The strange looking plastic pipe on the left is a home made sulfur discharge vent, since the old metal one corroded and goobered up the threads it was screwed into.  The first 50 feet of the well is surrounded by concrete to keep ground water from contaminating the well.  Most of that 50 feet has only a couple of inches around it, but the cap has a much wider pad to protect the well head from lawn mowers and the like.

And here we see what it looks like with the well seal opened up and the first couple of feet of pipe extracted:

The electrical was disconnected, the sulfur vent removed, and the union in the water line opened up.  At this point all 380 feet of pipe are hanging from a cable on a truck designed for this purpose.  It looks like this:

That picture was taken a bit later.  You can see a 20' length of schedule 80 PVC pipe hanging from the rig.  The pipes are threaded and attached with brass couplings.  An odd looking device is used to clamp the pipe in place while the section above is disconnected and set aside.  Here's a closer view of that:

The metal thing sitting crosswise at the bottom is the above mentioned clamp.  The technician is using the lift to pull the pipe up.  His assistant is pulling the electrical wires and a safety rope off to the side to keep them out of the way.  (Note that those wires and rope are taped to the pipe at regular intervals, so the tape has to be cut and removed as each pipe is pulled up too.)  Also as the pipe comes up the technician wipes the accumulated slime off of it.  And in our case there is a lot of that slime.  Some combination of iron and sulfur bacteria make for a nasty thick layer of gunk all over everything.  (And there will be a better picture of that later.)

As the end of the 19th section of pipe comes out of the ground, we see the well pump emerge, and just before that, a surprise:

OK... this may not look like much to the uninitiated but that's bad.  Most of the PVC pipe above the pump is 1" diameter.  The last two sections are 1.25" for some technical reason, but they do NOT bow out like that.  That's bad.  That's very bad.

What it means is that sometime a month or more ago the pump ran, pumped all the water out of the well, but then did not turn off.  As it kept running it got hot, since water is the usual coolant for the motor.  As the pump got hot it heated the pipe above the pump got too, and the plastic softened.  Eventually it got so hot - despite there being water inside the pipe - that a hole opened up in the pipe and the water drained out.

So that bowed out area just above the pump is a bad thing.  It means that something is wrong with the pump, the pump controller, or both.  Now, as it happens, we had a long brownout or two just over a month ago during a big wind storm.  For one of them I was home and awake and ran around turning off breakers, though I honestly don't remember if I got the breaker for the well pump or not.  I should have, but who knows.  The other brownout, if it affected us, hit while I was asleep, or so I gather from a neighbor.  The first was something like 20 minutes long and I have no idea about the other, but either might have caused a fault that could result in this sort of behavior.

Or there might be other causes.  Time will tell.

Here's a picture of the entire well pump sitting on the pad around the well:

The top half is the impeller, the bottom half is the motor.  Water enters through the grid in the middle and we can see that isn't too blocked up.

Here's a closer view of the slime from the well and the bottom of the pump.  I hope you haven't eaten recently:

Yeah.  Sorry about that.

And finally, here's the pipe from the well laid out ready to go back in once the problem is fully diagnosed:

The bulge in the last pipe is pretty obvious there.  The large, black, football shaped thing two pipes over from the left is a torque arrestor, to keep the pipes from twisting and banging around when the motor kicks in.  It fits just inside the six inch plastic pipe that lines the well.

My well guy took the pump and controller off with him today.  He will clean up the pump, bench test it all, and find the problem.  If the controller is bad he will replace it.  In addition - since this is the second time we've seen that pipe bulge up due to a hot pump - he may replace the last 20' section of PVC with stainless steel, to reduce the chances of that happening again.  (Of course, if it does happen the stainless will conduct heat better, and it might just move the problem, or it might cause the pump to burn out once it has run too long.)

Hopefully tomorrow he will be able to tell me exactly what failed, and we can start looking to avoid the root cause of the problem.  That may mean trying to find some way to protect our entire home from brownouts.  We already have a whole house surge protector installed, but nothing keeps a brownout from crippling us.

More when we know it.  Whee.