Seeking shallow well pump debug advice.

Discussion in 'Pumps and Tanks Well Forum & Blog' started by bugs11, Dec 22, 2007.

  1. bugs11

    bugs11 New Member

    Messages:
    3
    How does one tell if a shallow well pump is worn out (needs replaced)?

    My current set-up; a 13 year old 1/3 h.p. AY McDonald model 8310 cast iron pump sitting on top of a large pressure tank, 3’ of 1 ¼” pipe, new brass check valve, two new 4’ sections of 1 ¼ galv. connected to a new 48” 1 ¼” Johnson stainless steel sand point. So from the pump to the tip of the sand point is 15’. The sand point is in 100% sand and in the water table. The new stainless steel sand point gives at least 30% more surface area than the old 36” brass sand point. The pressure switch with the old point was set at 30/45.

    Here’s my story. Yesterday morning I woke up to the pump running and no pressure. I immediately went down and shut off the pump. The pump housing was warm to the touch but not hot. I called a friend who is a pipe fitter and he advised I go purchase a 36” or 42” stainless steel sand point, which I did (42" Johnson SS). Early in the afternoon he came over, we pulled the old point and put in the new one. The pressure gauge on top of the pump was clogged up, so he installed a used one he had on hand. We also verified that water was getting to the pressure switch. Now the pump will only pump at most 28 p.s.i. Also when I turn off the pump, close the valve to the house, and open the pressure tank drain little or no water comes out. The pressure tank has 32 p.s.i. of air in it. If I turn on the pump, good water gushes out of the pressure tank drain valve. My pipe fitter friend was of the mind that pump might be damaged. Right now I’m just trying to determine what’s going on. If the roads are passable tomorrow (blizzard going on outside at the moment) I’ll get to a big box and pick up a new pressure gauge. I don’t think this used one is giving accurate readings; the pump is running and the gauge shows 12 p.s.i., I manually activate the pressure switch on and off, then the gauge will show 28 p.s.i.

    Finally, I know what finally caused the old sand point to give out. The hallway bathroom toilet tank fill valve failed, the toilet tank was slowly continually filling. The hallway bathroom is the one the kids use and I’m sure they didn’t notice it. I only found it when I saw the pump gauge lose pressure and I knew every faucet in the house was closed. Process of elimination, it was the toilet.
    Last edited: Dec 24, 2007
  2. speedbump

    speedbump Previous member

    Messages:
    4,540
    Location:
    Riverview, Fl.
    The jet in that shallow well jet is plugged. That means you have a lot of either iron or sulphur that coats the pipe then breaks off in pieces and plugs jet nozzles.

    A new pump would be a good idea, as the inside of your old one is going to be pretty nasty.

    bob...
  3. bugs11

    bugs11 New Member

    Messages:
    3
    Bob, Thanks for the advice. Your right about the corrosion, for some reason their was substantial corrosion at the juncture of the galv. pipe and brass check valve. To the point where the galv. pipe was just about eaten through. Inside the check valve is a ring of black corrosion where the galv. pipe ended. I also had substantial corrosion at the diadatic (sp?) coupling coming off the pump to the copper supply lines. My pipe fitter friend doesn't know why the corrosion is happening.

    A new gauge shows the pump only pushing 25-28 psi tops. My pipe fitter friend talked to a well installer and he said their might be something clogging the venturi. So... we're (pipe fitter friend and I) going to take apart AY McDonald 1/3 h.p. pump this afternoon and see if we can un-plug whatever is plugged. As a back-up plan, I went and picked up a 3/4 h.p Flotec jet pump from the local big box; in case we need to replace the pump.

    On a side note, I was able to get the toilet fixed without replacing the fill valve mechanism. I took the cap of the Kohler toilet fill valve off and removed a piece of debris that was preventing the valve from closing.
  4. speedbump

    speedbump Previous member

    Messages:
    4,540
    Location:
    Riverview, Fl.
    It won't be the Venturi that's plugged, it will be the nozzle in front of it.

    You were doing real good until you bought that FloTec.

    If you think you have problems now, hook up the Flotec and they will double.

    bob...
  5. bugs11

    bugs11 New Member

    Messages:
    3
    Bob,

    Thanks for the input. The pump is fixed. I'm a volunteer fire fighter/first responder and just my luck we had an empty house catch fire this afternoon. So I was working a fire when my pipe fitter friend came over and got the pump working. I just called him on the way back from church, the Xmas Eve Candlelight service... anyway he said he pulled the plug on the end of the pump and cleaned out the jet. Took him about 15 minutes. The pump is now making 44 psi and cycling normally. Now I just have to make sure the pressure tank has 2 lbs. less than the cycle on psi. I think the pressure tank has 18-20 psi.

    The Flotec was just in case we dorked up the McDonald pump trying to fix it. I'll be happily returning the Flotec to the big box day after tomorrow. If I ever have to replace the 1/3 hp McDonald pump I'll get a Grundfos MQ or another McDonald 1/2 or 3/4. Oddly enough I was able to google up info. on the AY McDonald 8100 series of shallow well pumps. AY McDonald apparently does not make a 1/3 hp pump anymore.

    Again, thanks for the advice... hope I don't need anymore for some time.
  6. speedbump

    speedbump Previous member

    Messages:
    4,540
    Location:
    Riverview, Fl.
    Glad you got it fixed.

    I wouldn't be so fast to buy a varispeed pump. The A.Y. Mcdonald pump is a great pump. I can sell them, but they are a little high priced. They haven't gotten used to Florida's low low pricing yet.

    bob...
  7. Wet_Boots

    Wet_Boots Sprinkler Guy

    Messages:
    798
    Location:
    Metro NYC
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