I inherited a house and the water system has been giving me fits since I moved in a couple of week ago. The well will run for about 1.5 minutes and then shut off for about 3.5 minutes and then it kicks back on.

Here are some specs. The well is shallow with a 25ft pipe and water at 15ft I've been told. The pump is a 1/2hp jetpump with a 30/50 switch (new). I installed a 30 gallon diaphragm tank set to 28psi the other day because the old one was completely waterlogged and I hoped it help somewhat and it did, but just barely.

The whole system is flaky and I'm going to start going through it tomorrow starting at the foot valve because I suspect that's where the water is going and there are a couple of little drip leaks, including one visible one at the inlet. I figured I may as well check the entire system.

One thing that really bothers me is that the outlet of the pump is reduced down to 1/2" into and out of the tank. Unfortunately the whole system is 1/2" (Yeah I know. ). I'm definitely planning on replacing the plumbing from the pump to the tank to 1" tomorrow, but the 1/2in line into the house will have to wait a bit.

Another thing I noticed after I installed the tank was that it didn't seem like there was a whole lot of water in the tank. I let the pump run a full cycle and then shut it off to see how much water I could draw and it was only like 3.5-4 gallons which I thought was odd. Would 1/2in pipe from the pump to the tank cause such a thing or is it a sign that the pump is failing?

I'll post more tomorrow after I get a little deeper into the problem and see what I find. Any insights, comments, or questions would be greatly appreciated.

Jay

 

Welcome to the forums.

The actual water storage capacity is usually about 30% of the tank so a 30 gallon tank really holds about 8 gallons of water and only a part of that under usable pressure. The pressure tank is there to keep the pump from running every time a small amount of water is used.

Is the pressure coming up to 50psi..... the pump stops....... and then in 3.5 minutes the pressure goes back down to 30psi and restarts ?

See if there is shutoff going towards the house. Close this to isolate the house from the well. Does the pressure still drop as fast ? If it does it's probably leaking back into the well and it could be a leaking foot valve.

 

Hi Pjmax!

I knew they didn't hold a lot of water, but I wasn't sure about the exact amount. Yes, the well runs until the pressure switch turns the pump off and then it turns back on when the tank drains down. The pressure switch is brand new and I installed it with the new tank. It's one of those ones that's attached to the side of the pump with a little tune that goes to the pump housing.

There is a shutoff under the house, but I really need to fog under there before I make the crawl. I'm going to include one in the new plumbing between the pump and the tank and a pressure gauge, but it'll be after the tank. I inspected the inside plumbing when I got the place and aside from a toilet flap leaking a bit (Full tank leaks down to about half full in 8hrs when the water is off.) I didn't notice anything.

I'm going to install some valves to help diagnose the problem. Thanks for responding!
Jay

 

Everything from what you describe sounds normal to me. I do think replacing the 1/2" main line(s) with 3/4" is a good plan though.

 

You mean cycling every 3.5 minutes is normal? I just worry that the pump will wear out prematurely or the motor will burn up. Plus, I don't want to get blindsided by a $400 electric bill for the month.

Thanks!

Jay

 

No, that part (cycling every 3.5 minutes) is definitely not normal. You have a leak somewhere. A leak that is pushing out a gallon per minute of water. Anyway, if you pull the foot valve up and the system is under pressure you should see the leak quite clearly and be able to fix it up. This is assuming that it is a leak between the pump and the foot valve. It can be a leak anywhere and being able to shut off the house is a good way to help isolate it. It also helps prevent damage if you have a pipe burst in the house some day. If you can't shut off the house you will end up with 4 gallons of water in your house that you cannot stop...more if you set it up right.

As mentioned a 30 gallon tank does not supply 30 gallons of water. The way a pressure tank works is that you fill the diaphragm with air to about 2 or 3 psi below your cut in pressure. Did you do that? This air is added when the water system is under 0 pressure (tank empty). The reason for this air is that when the water is pumped into the pressure tank, that air is compressed to 50 psi before the pump shuts off. Now when you open a tap, that compressed air pushes the water out the tank to you until the pressure drops to 30psi and then this cycle repeats. Without the air pressure you will not get water pressure.

If you set the air pressure right that tank should supply around 7 gallons of water. So even if you did measure the air to be 28 psi, I know from the laws of physics that it is not or your pressure switch is not coming on at exactly 30psi.. If the air is set at 28 psi AND your pressure switch is coming on at exactly 30 psi then you would get around 7 gallons of water. Since you are not there is something wrong. I would guess your air pressure is a little low. In either case more air will give you more water. This more air equaling more water works right up until the air pressure is higher then the cut in pressure. At that time a new problem would surface. The air would push ALL the water out of your tank, before the pump turns back on, and since a pressure tank cannot exert pressure on water that is not in the tank you would get short little noticeable pressure drops just before your pump kicks on. Anyway, your tank could easily take a few psi more air without any problem from what I see.

So that is how it all works. You do need to find the leak and fix that. The air pressure issue is more of a maximization of the system then it is a necessity. If you are happy with 4 gallons of water, leave it. Good luck.

 

If you're going to swap out to a 3/4" or 1" pipe anyway, wouldn't installing a check valve into the new section of pipe from the pump to the pressure tank be the easiest solution to the problem?

 

The problem with that is that the pressure switch is most likely on the pump and it would not like being cut off from the pressure tank. The check valve would need to go on the other side of the pressure switch for the system to work right (between the pressure switch and the well). I believe most people put the check valves on the pipe going into the intake of the pump. The only issue is that one needs to give consideration to how they will prime the well pipe if they ever need to do so in the future.

The best solution is to find the leak and fix it.

 

Yep, just re-read the OP, and you're right, the pressure switch is on the pump.

 

Again, this sounds normal to me when somebody is using the water. If this is happening when nobody is using water, then you likely have a leak.

 

Tolyn Ironhand - I apologize. That's the behavior when nobody is running any water in the home.

 

Well then, sorry for the misunderstanding.

I would also say you have a leak. If you can isolate the system between the well and the house you should determine whether the leak is at the house or in the well. Do you happen to have a slab on grade?