Deep well jet pump turns on with no water use

**Jaytills** · 03-31-2012, 07:01 AM

Hello, I have a deep well jet pump that keeps turning on every 30 minutes even when not using water. The jet body was replaced a year ago and everything was ok until about 2 weeks ago. I've had a plumber here twice already. They replaced my pressure seating foot valve with a spring loaded one. then had to replace that one because it was damaged. The strainer was bent. Each time the system seems fine when they leave. I run water from the bottom of the tank for a few hours to get rid of sediment but then after that the pump goes back to turning on every 30 minutes. The tank was tested and is ok. I've isolated the house by closing he ball valve between the tank and house and still loose pressure. The lines going from the house and into the well were pressure checked by removing the exsisting pressure gauge on the pump with one with a shrader valve. The ball valve between the pump and tank was closed and then a compressor was hooked up and the lines and pump were pressurized to 90 psi. There wasn't a noticeable pressure drop. Im really not sure where to go from here. Do I have them issolate each line and pressure check them separately? Any help would be appreciated.

**LLigetfa** · 03-31-2012, 07:16 AM

You still have a leak between the well and the pump. Depending on how much air is in the line, pressure testing with air is much slower to show a drop than pressure testing with water. How many gallons of drawdown does it take to turn on the pump?

Maybe the footvalve is leaking again. Just because it was replaced twice does not rule it out. If you are having to flush crud out of the tank, crud might be preventing the footvalve from seating well.

**Jaytills** · 03-31-2012, 08:15 AM

Thanks. I didnt realize the air would show slower. Im leaning towards checking each section of line separetly and letting it sit a while to see what happens before i start digging holes. I did a crude test and found that 2-1/2 gallons of water was required to start the pump again. I waited for the pump to stop and then measured how much water came out until pump kicked in again. I ran the hose out of the bottom of the tank until it was completely clear and have been taking water out of faucets to test. Everything seems clear of sediment. It was just the initial sediment from pulling the jet assembly.

**LLigetfa** · 03-31-2012, 08:27 AM

OK, so we know that you are losing about 2.5 gallons over 30 minutes. That is not a very big leak. Water will not compress like air does so a slow leak would take longer to show a pressure drop with no water in the pipe.

2.5 gallons of drawdown may not be ideal and could cause the pump to short cycle. A 10 GPM pump would take only about 15 seconds to refill that tank. It should run for at least a minute, and longer is better.

**Jaytills** · 03-31-2012, 08:56 AM

I'm going to see about getting the fittings I need and the same kind of gauge the plumber had so I can test the lines from well to pump separately. Then I'll check the lines going into the well. Am I right in thinking I can put a plug at end of discharge line and then the gauge in the suction line and keep the jet assembly in the well?
Also, the pump runs for about 40 seconds or so with no water being used. The pressure switch is set to turn on at 40 psi and off at 60. The tank bladder is pressurized to 30-35 psi. Don't remember what the plumber set it at.

**justwater** · 03-31-2012, 12:30 PM

how old is the well? what diameter is the well? is it a 2 pipe jet assembly or a single pipe packer jet assembly.

if its steel well with a single pipe jet assembly, sounds like the casing could have a leak.

**johnjh2o1** · 03-31-2012, 01:42 PM

How would a leak in the casing cause the pressure to drop?

John

**LLigetfa** · 03-31-2012, 02:06 PM

On a packer assembly, the casing acts as one of the pipes in a two pipe deep well setup.

**johnjh2o1** · 03-31-2012, 04:01 PM

Originally Posted by LLigetfa

On a packer assembly, the casing acts as one of the pipes in a two pipe deep well setup.

If you read his post you will see he has two lines going down the casing.
John

**justwater** · 03-31-2012, 09:05 PM

I won't argue that "the lines going from the house and into the well" does make u think 2 pipe jet. but it's not uncommon for an offset pump to have 2 lines running to a 2-3" well with single pipe setup. with the limited info given, I thought it might be worth mentioning. feel free to disregard.

**Jaytills** · 04-01-2012, 09:06 AM

Justwater. Sorry for the confusion my lack of knowledge about well systems is apparent. I thought that a deep well jet pump always uses 2 pipes while a shallow well jet pump would always only use 1. That is why i thought the description was adequite. Yes, John is correct in that it is a 2 pipe system all the way down into the well to the jet body assembly and he's helped me formulate a plan to diagnose the problem. It is a 4" casing and there's actually 2 sets of pipes and 2 jet bodies since its a shared well. My assembly goes down 25' while the other one is about 5' deeper.