Irrigation Pump Pressure Problems

Discussion in 'Irrigation' started by bendc003, Jul 25, 2006.

  1. bendc003

    bendc003 LawnSite Member
    Posts: 7

    I am a homeowner and I am having problems with the pressure on my home irrigation system. My well is only connected to my irrigation system and it is controlled by the sprinkler control box. I replaced the box about a year ago because the first one was damage by water getting into the box during the 2004 hurricanes. About three months ago my well started to fluctuate the pressure in the system during watering. At first it didn't happen every time and when it did it may not happen through all of the zones. The fluctuation was accompanied by a loud thumping noise in coordination with the water pressure fluctuations. I just figured that we were going through a drought at the time and the water table was low or something. Now it has gotten worse. The thumping and the water pressure fluctuations happen every time consistently. We have gotten tons of rain so I know that isn't the problem. Also, now the thumping happens when the well is supposed to be off between watering cycles. About every 10-15 seconds the well does a single thump. I have looked at the pressure gauge when this happens. The gauge shows 90 prior to the thump and 100 after the thump. It then slowly goes back down until it reaches 90 again and the well thumps again. I have also noticed that this is what happens when the system is running as well. If when the system is running I open some of the pressure release valves on the well and let some of the water out it starts to thump faster until the pressure drops below 80 and then it stops thumping and the system runs fine with no pressure fluctuations. I am trying to find out if this is something I can fix myself since I am very mechanically inclined or if I really need to call in a professional to do the work. Any help would be appreciated. P/S: The well is about five years old.

    Here is a little more info on the well and pump.

    The tank is a Signature 2000 Fibrewound Pressure Tank,
    MOD: SR20-6S-01
    CODE: 1A02E 0120
    Drawdown-Gallons
    20-40 psi - 6.9
    30-50 psi - 5.9
    40-60 psi - 5.2

    The Pump is a Franklin Electric
    Model: 2801084915
    1 - HP
    230 - Volts

    The Pressure Control Valve is a PumpTrol SquareD

    The Sprinkler Control Box is an Orbit 6 station
    Model: 57976
    It is running only 4 zones.

    I have done some more research and I believe the problem might be that the pressure control valve might be out of adjustment (too high or too low, I don't know which) and the pump relay on the sprinkler control box may not be on properly causing the pump to always be on. I know this may be the case because there is power running to the well even when the sprinklers are off. Also, My pressure gauge on the well may be broken, when I tap on it the pressure falls faster and actually falls all the way to 50 psi, not the 90 psi I originally thought, then the pump cycles on for a split second and the pressure jumps to over 100 psi then within 15 seconds it goes back down to 50psi. Is there a leak in the system or does it automatically release pressure when the pump shuts off? I don't have any of the original documents that came with the well or the control box so I don't know how to adjust the settings on the pressure control valve or the proper settings and wiring on the sprinkler control box. Also, if I need to replace the pressure gauge, how do I do it since the connection looks corroded and where can I get a replacement gauge and what type am I looking for. Sorry, I know this is quite a bit to ask and you are all very busy professionals but I need to find out what is going on and how urgent it is to get this fixed, money is a little tight right now. Thanks for any help you can give. Chris
     
  2. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,017

    Replace the gauge. They are almost always threaded into the system, and the gauge should have 1/4 inch male threads on the bottom. The pressure control might be bad, but you can do a bit of work and make it easier to deal with it. If the control is connected to a staight pipe nipple, that nipple can be cut out and replaced with two shorter brass nipples and a brass union connecting them. The union allows you to check and clear this short length of pipe, which sometimes gets clogged up with rust, and whatnot. The clogging can get into the pressure switch chamber itself. Usually you just replace the control switch when this happens, but some disassembly can give you access to clean out the water chamber.

    The other thing that might be wrong is that the pressure tank has lost its air charge, but you have to have a trustworthy pressure gauge in the system to check on this.
     
  3. speedbump

    speedbump LawnSite Member
    Posts: 117

    You said the well was controlled by the sprinkler timer. It is not, the timer just opens valves then the pressure switch turns the pump on. Since your tank is waterlogged and probably needs replacing, your pump motor is cycling. This is the worst thing you can do to a motor. If I was standing there like you listening to it go thump thump. My teeth would be gnashing.

    Next time go with a Well X Trol or Flexcon. They will out last the warranty.

    You might want to look into the Cycle Stop Valve as well. If your pump cycles like a lot of them do here in Florida that will also take out a motor.

    bob...
     
  4. bendc003

    bendc003 LawnSite Member
    Posts: 7

    Does the cycle stop valve replace the pressure control valve? And how do I know that the tank is water logged? And what exactly does that mean? And does it mean that I just need to repressurize the air in the tank or do I have to replace the tank? Chris
     
  5. speedbump

    speedbump LawnSite Member
    Posts: 117

    The Cycle Stop Valve goes between the pump and tank. It keeps the pump running while you are using 1gpm or more. Once the water usage stops, the valve will let the tank fill at the rate of 1 gpm. It basically protects your motor and gives constant pressure as a bonus. I would still replace the tank though. With the CSV you can go with a tank as small as 1 gallon if you have no leaks.

    It does not replace the pressure switch, it just works with it.

    If the tank feels very heavy, it is waterlogged. If the pump cycles rapidly while using water at about the rate of a garden hose, it's waterlogged.

    bob...
     
  6. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,017

    The simplest thing to do for a start, is to completely drain all the water out of the tank. I would be assuming a fiberglass tank would be a captive-air-charge type, which aren't supposed to get waterlogged. They could still lose the air charge, so you want to repressurize the air chamber to 50 psi or so, with a small air compressor, like you use for inflating tires. If you don't have one, any manual pump would do, given a great deal of patience. Most well guys would happily sentence negligent homeowners to several hours of bicycle-pump labor as punishment for letting a lost air charge go un-remedied.

    If the system is off, and the pump runs occasionally, that would possibly indicate a leaking check valve allowing the water to go back down the well.
     
  7. speedbump

    speedbump LawnSite Member
    Posts: 117

    50 might be a little high WB. Two pounds less than the turn on pressure of the pump is the rule of thumb. If he puts too much air in the tank, it won't let in any water at all.

    I had a customer call Monday. He thought his tank needed air, so he pumped it up to what his tire gauge said was 30 psi. When I got there the pump was going on/off, on/off you get the picture. He had put 70 psi. in the tank, so no water was getting in at all since his switch was set to go off at 60. I'm amazed he didn't blow up his motor.

    bob...
     
  8. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,017

    Even zero air would do, just for a start. That might be enough to see if the rest of the stuff is normal. I had a system that had to be connected to a 1/2 bathroom line, on account of the brain-dead home builders not making any provisions for sprinkler plumbing. By the time I got the system and well pump balanced, I was running around 90 psi at the pump tank. Poor little cigarette-lighter tire-inflator compressor I was using at the time had its last hurrah inflating the tank charge to around 70 psi.
     
  9. speedbump

    speedbump LawnSite Member
    Posts: 117

    I can imagine it could do some damage to one of those. My wifes car has one in the trunk. I used it on a trip not too long ago. When I reached in to unplug it from the cigarette lighter, it burned my hand. No more of that.

    Another thing with bladder tanks. If you don't put enough air in one and put too much water in it, you can tear the bag loose completely. Especially in those WX-203 tall Well X Trols.

    bob...
     
  10. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,017

    Gee, I'd think they'd want to design the tanks to avoid internal damage in the event of air loss.

    I used a manual tire pump one time, decades ago, to charge a waterlogged standard galvanized tank at a relative's house. No 70 psi there, thank goodness. Every air bubble that escaped the tank while I tweaked the pressure switch was painful to hear.
     

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