Help! water pressure tank hitting 100psi!

Plumbing Forums

Help Support Plumbing Forums:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

narhic92

New Member
Joined
Sep 3, 2024
Messages
2
Reaction score
0
Location
Pisgah forest, NC
In a 2 week time span, Our well water pressure tanks have hit 100 psi, multiple times. It happened first on Labor day, yesterday, and tonight( maybe even more, I work during day so I'm not home till after 7pm). First time I noticed it was on Labor day. I noticed the water pressure in the house was up and the toilet was constantly running. I went under the house to check what the pressure tank gauge was reading and it wasn't even registering anything. The needle on the gauge was pointing straight down. I thought the gauge, even though pretty new, must've quit working. There appeared to be water on the pipes like it had been sweating, or leaking or something. I then went outside to check the well pressure tank that's connected directly to the Well pump and it was showing over 90psi{its usually a little lower then what our tank under house reads}
We are one of two houses that share the same Well. The well pressure tank connected straight to the well pump outside stores water for the neighbors house. this is what the outside well tank look like...by the way this is after the water pressure went down and not the reading when it was HIGH. The pink stuff is insulation.

outside pressure tank.jpg

He has a gauge inside his house that reads what the gauge says on the pressure tank outside that connected straight to well. Its a relatively new gauge and It works properly. Another pipe, seen in pic above, connected to the outside tank feeds water to our well pressure tank under the house.
under house pressure tank.jpg

This is our tank under house. This pic too is after the water pressure went down. It was ready 40psi at time of pic. Normally our gauge attached to our well pressure tank under our house nearly matches readings with outside tank gauge. Heres a close up pic of the info for our tank under house:
upclose pic of tank info.jpg

Our well pressure tank under the house is about a year old. Had to replace old one cause the T valve connected to the pressure tank rusted out and blew last year. Was not an enjoyable experience cause I had NO idea what happened, and having ZERO experience with Well pressure pumps or tanks I didn't know how to shut the water off. All I knew was that water was beginning to fill up underneath the house and I didn't know what to do. I thank the one business we were able to get a hold off who explained to me how to turn the well off and allowed us to notice the rusted out T-junction, lol. Long story short we replace our pressure tank under our house, seen in 2 pics above and again that was replaced last year.
The well pressure tank under our house serves just as a water tank. Though there is a Well pressure switch on it, as seen in second from the top, its not connected or serves any purpose to our tank. I'm guessing at one point in time it did but things must have been changed around before we moved in. The fact of it not being connected, probably saved me from electrocution when the water was spewing out when the t-valve busted.
Now, once the new pressure tank under the house was installed we begin having issues with the pressure becoming elevated. Normally the psi on the pressure tank never went above 50 psi and they were hitting up to 70psi's after the new install. My brother adjusted the Well pressure switch box connected to the tank outside and that seemed to fix the issue and that was that(The well pressure, for both houses, can only be adjusted on the outside tank pressure switch on first pic up top). Please don't ask why the way things are set up when it comes to the well system...I just live here and am supposed to be Mr. fix it, lol.
Now, Jump ahead almost a year then this happens. In the 2 weeks since we've had the issue I go down under the house every day to check the pressure tank gauge psi(Turns out the gauge wasn't busted the water pressure just must have been to high for the pressure gauge to register and it started registering once the water pressure went down again). Over the 2 weeks , Sometimes it says 50psi, 60psi or close to 70psi. Tonight, as stated above it did it again and was at 100psi. Water was leaking at pipe connection points. I caused the pressure to go back down by turning the water hose on for a while.
What could be causing the issue on the Psi fluctuate and it going so high. I think the Well pressure tank switch is well over 20 years...could it be malfunctioning and could simply replacing it Aleve the issue? What are some other things that could be causing the issue? Is there any diagnostician i could do to narrow the problem? I moved in my family's house a year ago and I'm supposed to be Bob Villa according to my sister and Mom, lol. I think i feel like Tim the tool man Taylor lots of time, lol.
Any help in solving this issue would be greatly helpful. Thanks for any and all help!
 
The well pump is the source of your pressure. If the well pump is providing higher pressure than the set pressure on the switch, the switch isn't turning off the pump.
 
As was said, check the pressure gauge. If it goes to zero when the tank is empty the gauge is probably good. Pump not shutting off could be the nipple to the pressure switch clogged, or a bad switch. But it should never get to 1oo PSI as there should be a 75 PSI pressure relief valve in place of one of those plugs on the tank cross, and it should be leaking water at 75 PSI.
 
Hey guys, I appreciate the help and I thank you So very much. So, I tested pressure switch voltage and it was only ready 112 volts instead of the 240 volts. I bought a new pressure switch and am about to install it, that is after i figure out which breaker box switch outside kills the juice to the pressure switch. I hope new switch fixes the issue.
 
Last edited:
How did you test the switch? Each leg WILL have 110 to 120 volts. The two hot wires will show 220 to 240 volts if the breaker is not malfunctioning.
And if your 220-volt pump only has 110 volts going to it, I guarantee you that will NOT cause your pump to over pressure your system. It will actually not pump at all. But if the switch is bad, that could resolve your problem.

I am assuming that your description of how you resolved the "overpressure" by "turning the water hose on for a while" caused the pressure gauge to show that reduction.
 
Back
Top