I don’t know much about well pumps.
I have a well pump that keeps running. The inside of the cover of the switch reads On at 20 Off at 40. However, what is happening is the pump comes on at 30 and pressurizes all the way up to 70. It takes about 5 mins to reach 70psi. Once it reaches 70psi it runs for about 20 minutes before it shuts off.
How do I fix it?
I assume this the pressure switch is bad and I just need to replace it? If I do that do I have to drain the water from the tank and purge all the pressure?
The bladder reads 50psi with a tire gauge.
Replies
It sounds like the pressure switch is bad, though check first to make sure there's no cutoff valve between the tank and the pressure switch that might be causing the switch to misread.
To replace the switch you cut power and run the water until it stops coming out, then replace the switch. No need to depressurize the bladder -- just leave that alone.
Thanks.If at first you don't succeed, try using a hammer next time...everything needs some extra persuasion from time to time. -ME
Don't know that much either but sounds like a leak in the line from pump or bad check valve. If it is not shutting off until 70# then either adj on switch is bad or switch is not right. The pressure on tank is normally about 2 psi below cut-in pressure.
I set mine for 45 cut-in and 62 cut-off. The pressure is in tank is measured with the pump off and all water pressure off, in other words a faucet/other drain open until no water comes out. While sort of draining the tank it is not necessarily drained. You can do it with a faucet that is higher than the tank and not actually empty the tank.
Turn of the pump and drain the system. Then check the tank pressure.
You probably have a bad switch and a blown bladder tank.
Is that your Makita charger again?
If the pressure gauge really shows 70 and you hear the pump bypassing I vote for the switch too. A bad tank causes short cycling.
When it is up to pressure, turn off the power to the pump, open a valve and watch the water pressure gauge. It should slowly drop as the water goes out of the tank. When it suddenly drops to zero and the water stops, the last reading you had when it was squirting water is the precharge pressure in the tank. That is a quick way to check it.
If a big gush of air comes out after the water the bladder is probably leaking, particularly if you have added air a few times.
You might try cleaning the points in the pressure switch.http://www.tvwsolar.com
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The bladder is fine at 50psi with the tire gauge. I've not added pressur at all to the bladder. So the bladder is not leaking at all.If at first you don't succeed, try using a hammer next time...everything needs some extra persuasion from time to time. -ME
You say the pump is running for 25 minutes before shutting off. If the bladder is fine, where is all that water going? What is the gpm for the pump and how big is the tank?
He could be getting the pressure so high the pump is stalled, and just making heat, or the pump has a bypass valve built in, that is just dumping water back into the well.
The tank is a pressure vessel, so it will hold pressure on it's own with a bad bladder. The bladders serves to keep the water isolated from the tank walls. Which is mostly to keep the water cleaner, (if the tank starts to rust, the rust would get in the water with out the bladder), and keep the tank itself from corroding as fast.
The bladder also allows a "50-gallon" tank to be only the size of about 30 gallons.
The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith
The bladder also segregates the tank air cushion from the water passing through. In an old style no-bladder tank the air cushion is constantly depleting as the high pressure drives the air to dissolve into and be carried away by the water that temporarily resides in the tank.I used to have to recharge the air cushion on my old style tank almost bi-monthly. I check the pressure on the bladder tank I replaced it with every couple of years and it hasn't needed a recharge yet.
I had a similar "running on" problem with a shallow well pump. As the impeller wore, the max pressure out of the pump decreased until it was down to the cut-off pressure, at which point the pump would run for a long time before cutting off. In the short term, I solved the problem by lowering the cut-off pressure to be below the pump max pressure and in the long term by replacing the impeller.
Sounds like a problem I had about 20 yrs ago. I ended up replacing the whole pump and tank with no fix. Bad thing, I had to dig up the well and pull the pipe out of the tank, It ended up being the check valve at the bottom.
Forgot to mention. It was in the begginning of feb and the highest it got that week was -5 !!!
I am hoping for you it is the preasure switch!
Edited 2/5/2009 4:55 pm ET by frammer52