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View Full Version : Well pump won't hold a prime


mx315
05-28-2008, 01:11 PM
I have a new Sta-Rite pump that will hold prime for a few days and then all of a sudden it leaks down and will not shut off. I replaced the check valve about five weeks ago, when I moved the welll pump over about two feet. It worked about four days, then the pump was running when I came out one morning and I had to turn off the breaker. I could hear water run out of the pump back into the main line, so I figured it was a bad check valve. When I removed the old check valve I poured water into it and it leaked through so I was sure that was the problem. I replaced it with another one last week and it's doing the same thing. It has been working fine for about 4 days and I came out this morning and the pump was still running. I turned on the faucet on the outlet line and the water still comes out with good pressure. I turned the breaker off and the water starts running back into the well pipe. I flipped the breaker back on after about a minute and there is no prime again. It's a 2" PVC check valve from Lowe's... maybe a batch is the only thing I can think of.

BrandonV
05-28-2008, 01:22 PM
It's a 2" PVC check valve from Lowe's... maybe a batch is the only thing I can think of.

problem solved, go to a pluming supply and get a brass foot valve, attach to the end of the line in the well and profit.

mx315
05-28-2008, 03:28 PM
Thanks, that's the only thing I could think of.

Dirty Water
05-28-2008, 08:05 PM
Stop putting the check valve on backwards :)

BrandonV
05-28-2008, 08:21 PM
Stop putting the check valve on backwards :)

touché dirty water

Waterit
05-28-2008, 08:35 PM
Trying to figure out the "will not shut off" part. Is it on a tank with a pressure switch?

Bigred350
05-28-2008, 10:15 PM
It like Tom said Cut that plastic crap off and put a brass 2" FOOT VALVE on it. I have installed hundereds of them and have hardly had any problems out of them.

mx315
05-29-2008, 09:32 AM
Stop putting the check valve on backwards :)

That was the first thing I thought of... because I have done that.

Waterit, it's on a tank. I haven't installed many of the sta-rite pumps, but the guy at Stovall told me that was common if they drop prime. He even told me that he's seen them vaporize water if it looses prime and runs for a long time.

Waterit
05-29-2008, 10:05 AM
I haven't installed many of the sta-rite pumps, but the guy at Stovall told me that was common if they drop prime.

It's only common if you have a bad check valve or leaky piping on the well side.

He even told me that he's seen them vaporize water if it looses prime and runs for a long time.

Oh yeah, I've seen them get so hot the pipe melts.

I'm going to assume you have a 1-1/2HP centrifugal. We've found over the years that those pumps don't work well with tanks - they simply don't produce enough pressure. If the tank must stay, try this:

Screw a 2" x 3 " long galvanized nipple into the suction (well) side of the pump, then screw on a BRASS check valve. Screw a 2" PVC male adapter into the check valve and reconnect to the well. Make sure to use pipe dope (NOT TAPE) on your threaded joints. And if you have a union or a T with a plug in it on the well side, get rid of them - they're not necessary and can leak. If you're sucking air you're not sucking water, and you'll lose your prime.

I'll try to post a pic later of how we pipe pumps up here.

mx315
05-29-2008, 10:45 AM
You're right it's a 1.5HP and the tank doesn't "have" to stay. I just reconnected it the way it was before. I used teflon pipe dope instead of tape and removed the union that was on there after replacing the first check valve. I have noticed that on some pumps, when connecting PVC into the pump inlet, they sometimes will work themselves loose... I guess from vibrations. I was thinking of using the 1.25" galvanized pipe for the inlet side because my outlet side has that for the tank and then connects to the 1" pvc.
I have been installing the check valve vertical, I'm guessing it's ok to install it horizontal if I'm picturing what you're talking about doing?
Thanks for the info

Waterit
05-29-2008, 10:57 AM
You're right it's a 1.5HP and the tank doesn't "have" to stay. I just reconnected it the way it was before. I used teflon pipe dope instead of tape and removed the union that was on there after replacing the first check valve. I have noticed that on some pumps, when connecting PVC into the pump inlet, they sometimes will work themselves loose... I guess from vibrations. I was thinking of using the 1.25" galvanized pipe for the inlet side because my outlet side has that for the tank and then connects to the 1" pvc.
I have been installing the check valve vertical, I'm guessing it's ok to install it horizontal if I'm picturing what you're talking about doing?
Thanks for the info

Is there a pressure switch involved in this setup? If so, tank has to stay. If not, get rid of it! Or you can add a pump-start relay to control system and do away with press switch and tank.

They work themselves loose by getting hot - when you lose prime the pump loses its primary cooling source (the water flowing through it) and the next thing to go is PVC threaded fittings on suction and outlet sides... One reason we use steel nip between brass check and pump.

Use 2" on the suction side - there's no need to reduce it unless well pipe is smaller.

Brass check can be installed horizontally, do it all the time. PVC checks only vertical mount - they jam too easily.

mx315
05-29-2008, 11:21 AM
There is a pressure switch, but I was thinking of getting rid of both and using the pump start relay... they seem like less trouble.
The inlet threads on the pump is a 1.25" that's why I was reducing, but I will use a 2" check valve and just reduce down to 1.25 after the check valve.
thanks again

Waterit
05-29-2008, 05:17 PM
What is the model # of this pump? Never heard of a 1-1/4" inlet OR discharge - maybe 1-1/2"?

What size is well piping?

AI Inc
05-29-2008, 05:39 PM
What is the model # of this pump? Never heard of a 1-1/4" inlet OR discharge - maybe 1-1/2"?

What size is well piping?

We plumb a lot of goulds with 1-1/4 intake.

Mike Leary
05-29-2008, 05:43 PM
There is a pressure switch, but I was thinking of getting rid of both and using the pump start relay... they seem like less trouble.

Much less trouble, as you get up to max pressure immediately. 60-40 switches
were not made for us. Could get into pressure problems, though, depending on the zone needs.

Waterit
05-29-2008, 09:11 PM
We plumb a lot of goulds with 1-1/4 intake.

I've seen those - love The Irrigator centrifugal, beats a Sta-Rite's pump curve all to heck - never seen anything but 1-1/2 and 2 in a Sta-Rite.

mx315
05-30-2008, 09:06 AM
What is the model # of this pump? Never heard of a 1-1/4" inlet OR discharge - maybe 1-1/2"?

What size is well piping?

I checked it again to be sure and it's 1 1/4 for the inlet side. The well pipe is 2".
Thanks Mike, I've ran this setup for about 7 years and it's been pretty dependable... so I guess I should leave it as is.

Waterit
05-30-2008, 10:27 PM
Here's a pic of how we pipe a pump...

Note the pressure relief valve doing its thing!

hoskm01
05-30-2008, 11:19 PM
I checked it again to be sure and it's 1 1/4 for the inlet side. The well pipe is 2".
Thanks Mike, I've ran this setup for about 7 years and it's been pretty dependable... so I guess I should leave it as is.
It has been evidenced, time and time again, that people from Florida dont hear about much in modern irrigation. THanks for reaffirming this for us.

RAlmaroad
05-31-2008, 05:44 PM
I have a new Sta-Rite pump that will hold prime for a few days and then all of a sudden it leaks down and will not shut off. I replaced the check valve about five weeks ago, when I moved the welll pump over about two feet. It worked about four days, then the pump was running when I came out one morning and I had to turn off the breaker. I could hear water run out of the pump back into the main line, so I figured it was a bad check valve. When I removed the old check valve I poured water into it and it leaked through so I was sure that was the problem. I replaced it with another one last week and it's doing the same thing. It has been working fine for about 4 days and I came out this morning and the pump was still running. I turned on the faucet on the outlet line and the water still comes out with good pressure. I turned the breaker off and the water starts running back into the well pipe. I flipped the breaker back on after about a minute and there is no prime again. It's a 2" PVC check valve from Lowe's... maybe a batch is the only thing I can think of.


Does your pump have a small bladder holing tank? If so, check the pressure on the tank--it should be 2lbs less than the cut-in in pressure i.e. 20spig cut-in-- tank should be 18lb. I did a service call and the pressure was at 38psig which pushed the water from the pump and made the pump run continuously

mx315
06-02-2008, 10:47 AM
It was the PVC check valve. I cut it out this weekend and it was hanging sideways inside the sleeve. I replaced it with a brass one, like waterit showed... and it's working well. Thanks for the help.

Wet_Boots
06-02-2008, 10:55 AM
All right! A satisfied customer. Brisket all around!