Plumbing is not my profession. I have little to no knowledge of plumbing except what I have read online, in books, conversations with others who have experience, and the trial and error approach.
Seven years ago, I made a mistake when installing my pressure tank, and we lived with that mistake until it failed completely. Our pressure tank failed, our cistern pump failed, even though the timing could not be worse for me, the system needed to be revamped, a patch job could no longer suffice.
Rewind to seven years ago… I installed the largest pressure tank I could afford and fit in my house. I believed the theory the larger the tank, the longer the life of the cistern pump. However, this theory did not hold true for a DC cistern pump that needed much more strength to handle such a pressure tank for long periods of time. I have now rectified this situation by installing a smaller pressure tank and putting it as close to the pump as possible. This should help ease the issues we have been having with the DC pumps.
Lately, our pumps have been dying at the year mark. Each year we have lessened our demand on the cistern pump, but my wife and I have noticed the quality of the pumps have decreased over time. Perhaps, the pressure tank failure has played a major part in that, perhaps not. If I am writing a post about changing a cistern pump next year around this time, then quality issues it is.
In the following video, I admit my failures and what I have learned from the trial and error approach concerning our home’s plumbing system. Having two water lines between the pressure tank and the cistern pump was a bad idea. We lived with a water hammer for seven years. At times the hammer was minimal, but lately it has been horrendous. Before complete failure, the cistern pump was turning on in the middle of the night with no water usage. At three in the morning, the water hammer would start for about 15 minutes to fill the failing pressure tank. The pressure tank eventually became water logged and could no longer maintain house pressure. The pump was the only thing pressurizing the house until the Square D would shut it off. Needless to say, this project became a 4 day nightmare as I discovered pumps that could move large volumes of water does not equate to maintaining the correct PSI. I lost another DC pump due to its age and already fatigued parts. Eventually, my irrigation pump became our cistern pump and provided our domestic water needs until a back ordered DC pump could arrive weeks later.
I am glad this adventure is finally over. The house plumbing no longer has a water hammer. The check valve and moving the smaller pressure tank closer to the cistern pump helped solve much of the issues. The two lines are now pressurized on the same side of the pressure tank as the rest of the home and this has been the singular issue that caused the noise we used to hear at each PSI recharge from the cistern pump.
Hopefully, you can learn from this amateur’s mistakes. If you are a professional plumber, you are probably shaking your head at me and using me as an example to others why your profession is desperately needed. However, even with all my mistakes I am still in the black because I never had to pay a plumber’s house call rates. At this point, I must weigh the physical stress I was under to create a domestic water system from a failed one full of mistakes within a four-day window while still meeting the requirements of my profession. Quite possibly next time, I will call a plumber, but knowing me and the possibility of receiving such a bill, I won’t.
Does anyone know what movie I based my thumbnail/featured picture off of for the video and this blog post? Place your guess in the comment section.
10 thoughts on “Fixing a 7 Year Mistake”
If my building mistakes take seven years to surface…I’ll be thrilled!
Your tiny house is beautiful. I don’t think you have any mistakes.
Do you know the movie title?
Did your submersible pumps have a rating for how high it can pump the water? If so, that can be used to guess the pressure rating of the pump.
Each “foot of up” of water is worth 0.43psi. So a pump that can move 1800 gallons per hour up 25 feet moves 1800 gallons of water per hour at 10.75psi.
I like where this is going. Perhaps you can help me complete the formula. The cistern outlet pipe is about 5′. The pressure tank is about the same as the outlet pipe. The highest pipe in my house is about 8 ft., but I also need to add 4′ because of the box the tank is buried in. So 17′ to lift approximately.
1800 gph at 15′ x .43 = 774/60 min. = 12.9 psi. Add a couple feet and barely 10 psi. Thanks. I was never taught this in school, and this is very useful to know. However, I doubt the majority of students today would care. Unfortunately, they see no need for math and physics, little do they know. As our society becomes more complicated and knowledge is specialized to certain careers only, it makes it difficult for a person to be self-reliant without the proper knowledge, and it can lead to mistakes as I have made. I wish I had known.
Does it matter the pressure tank is only 5′ of lift or does this formula need to include the whole system after the pressure tank as well?
The “lift” is from the top of the water within the cistern to the open faucet. So, as the water level in the cistern drops, the “lift” increases. The “lift” will include the height above the pressure tank.
What happens is the pressure at the bottom of a pipe and at the top of a pipe changes by 0.43 feet per foot of height. So, if you have 43 psi at the bottom of a 100 foot pipe, the pressure would be 21.5 psi at 50 feet and zero at the top of the pipe. This assumes the water is moving slowly or not at all….like cars’ friction due to wind, water in pipe can experience friction as well….
For a suitable pump (not a “sump pump”), the extra 8 feet won’t matter much as the 43psi (an example that isn’t too far off from reality and also makes for easy math) is equivalent to 100 feet of “lift”……
For what it’s worth, I saw this
My guess is there are two ways the pressure tank works…at high flows, the pumps are what does all the work and the pressure tank is there just to smooth out the pressure pulsations from the pump…and at very low flows, the pressure tank can slow the on-off cycling of the pump.
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As a wild guess, your pumps failed due to overheating because they ran much longer than normal when they were filling the pressure tank. Our tent trailer has a similar pump and when it runs, it’s cycling “on a few seconds, off a few seconds”. The worst use case for it is when one of us is showering, then the on-off cycling happens for a couple of minutes and then it gets to cool off for a fairly long time.
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Movie reference was “Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb”.
Perhaps, my choice of cinema was too obscure. It was, afterall, a flashback to 1964.