New low pressure issue

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Notable Noob

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Here is my issue. When taking a shower the water pressure is normal, then drops rapidly to no flow, in about 20 -40 seconds it picks back up. It does this on both hot and cold water. I have also had my washing machine give a low pressure warning. I believe it is my captive air tank but the pressure readings are normal (40/60). Do I need to replace the whole thing or is there a way to be certain? I prefer less expensive stabs in the dark. No new plumbing work has been done in over 6 years so I am fairly confident I didn't break anything. The tank is an A.O. Smith Aqua-Air water system tank V60 (20 gal).

I appreciate your time in reading my post.
 
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JG plumbing

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Take a picture of what you think the problem is. With the piping and components.
 

Valveman

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Sounds like the pump is tripping the internal overload. These will cool down in 30-60 seconds and the pump starts up again. A 20 gallon tank only holds 5 gallons of water. My guess is the cycling every 5 gallons has damaged the pump and it is now tripping the overload. It maybe too late to save the pump by stopping the cycling, but eliminating cycling is what makes pumps last longer as they are made to run 24/7 not cycle on and off.
 

RS

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Someone else had a problem similar to yours and I suggested maybe the line going to the pressure control switch was plugged, and I was right. Check that out, make sure your pressure control switch is working properly. Also depressurize the system and check the pre-charge on the tank, it should be 2 psi, les than the cut in. The way to accurately check this is to turn off the power, and then bleed off the water until the switch clicks. the gauge should move just another 2 psi and then drop to 0. You can use a tire gauge on the Schrader valve, but most tire gauges aren't accurate enough . Good luck
 

Notable Noob

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Sounds like the pump is tripping the internal overload. These will cool down in 30-60 seconds and the pump starts up again. A 20 gallon tank only holds 5 gallons of water. My guess is the cycling every 5 gallons has damaged the pump and it is now tripping the overload. It maybe too late to save the pump by stopping the cycling, but eliminating cycling is what makes pumps last longer as they are made to run 24/7 not cycle on and off.
Thank you. That makes sense. The logic makes sense and supports the issues I am seeing. I will depressurize like RS stated but my uninformed gut tells me Valveman is probably right. The tank is about 15 years old. I am guessing it would be best to replace it with a new one at this point?
 

RS

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I wouldn't be to quick to replace the tank! If you depressurize the system and set the preload in the tank to the proper pressure it will work fine with a bad bladder, for awhile, like 3 months. We have a cabin where I am using an old water heater tank for a pressure tank, I preload it in the spring when I start the system, and once more during the summer and it works great. I suspect you have another problem, good luck, let us know what you find.
 

Valveman

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It depends on where the bladder is torn and how much water you use as to how long and if adding air to a bad bladder tank will work. If you are replacing the tank, you don't need a very large one if used with a Cycle Stop Valve to stop the damaging pump cycles.


 

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