New well and undersized pump.

[Dennis6969]

So due to the lack of rain, my well ran dry. It was only at 125 feet which is not very deep for my area. . I was not able to drill the existing hole deeper due to collapsing inside the bore hole. Had a new well drilled, for a total depth of 320 feet. From what I’m reading water was hit at 153 feet and 275 feet, for a total flow of 15 gallons per minute. Static level of the water is at 80 feet the well installer installed a 5 gallon per minute, three-quarter horsepower pump at 300 feet. According to Goulds website, it is acceptable and within the pump curve to use that pump however, I feel my water needs are well more than 5 gallons per minute. With both showers is running my washing machine and dishwasher which happens often, the well pump cannot push pressure back into my tanks and continues to run. I have 2-44 gallon well tanks piped in tandem on a 40/60 pressure switch. With just the kitchen and bathroom sinks running it takes approximately five minutes for the pump to fill my tanks, well driller said that it’s good however, I feel that it is at least at the edge of my water needs if not completely undersized. Am I wrong if I ask for a bigger pump. It seems a 7hpm 3/4hp pump will be more sufficient for my needs and it is a bit more centered in the pump curve as well. This was a very expensive job and I want to make sure it’s right. Thanks again.

 

[Reach4]

With both showers is running my washing machine and dishwasher which happens often, the well pump cannot push pressure back into my tanks and continues to run.

That does not sound bad at all, and maybe ideal. You did not say the pressure drops low during those times. Does the pressure drop below 36 during normal events?

 

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[Valveman]

With the pump set at 300' and the static level at 153', you have 225 gallons stored in the well to use before the 15 GPM the well produces makes any difference. Even then the well makes 15 GPM, so the pump should have been sized to fit your needs as the well will do whatever you want. You can have a large a pump as you want.

However, most installers prefer to undersize instead of oversizing the pump. Like he said, running a long time is a good thing. The larger pump will cycle on and off rapidly, which is what causes pump failures. A 44 gallon tank holds 10 gallons of water. Two would hold 20 gallons total. That is also a reason for low pressure as you have to wait for all 20 gallon to be used from the tanks as the pressure falls from 60 all the way down to 40 before the pump is started. A smaller tank, or even removing one of those would help, as the pump would start quicker. Then to keep the pump from cycling itself to death with a small tank, adding a Cycle Stop Valve will solve that problem and deliver strong constant pressure to the house.

I would have used a 10 GPM, 1HP pump and a PK1ALT kit with a 20 or even one 44 gallon size tank.

 

[Dennis6969]

That does not sound bad at all, and maybe ideal. You did not say the pressure drops low during those times. Does the pressure drop below 36 during normal events?

No it doesn’t drop down below cut in. When the switch cuts in it will push but if a couple of fixtures get turned on it seems to hang instead of pushing the psi up. It may hang at 40-42 psi depending on where it was at when the extra call for water started. I understand it’s not the worst thing but a shower flow at 50-60 psi is different than at 40 psi. U feel it. My old pump used to push the pressure up with the two tanks in about 2.5 minutes so I didn’t feel the drop.

 

[Dennis6969]

With the pump set at 300' and the static level at 153', you have 225 gallons stored in the well to use before the 15 GPM the well produces makes any difference. Even then the well makes 15 GPM, so the pump should have been sized to fit your needs as the well will do whatever you want. You can have a large a pump as you want.

However, most installers prefer to undersize instead of oversizing the pump. Like he said, running a long time is a good thing. The larger pump will cycle on and off rapidly, which is what causes pump failures. A 44 gallon tank holds 10 gallons of water. Two would hold 20 gallons total. That is also a reason for low pressure as you have to wait for all 20 gallon to be used from the tanks as the pressure falls from 60 all the way down to 40 before the pump is started. A smaller tank, or even removing one of those would help, as the pump would start quicker. Then to keep the pump from cycling itself to death with a small tank, adding a Cycle Stop Valve will solve that problem and deliver strong constant pressure to the house.

I would have used a 10 GPM, 1HP pump and a PK1ALT kit with a 20 or even one 44 gallon size tank.

View attachment 102395

 

[Dennis6969]

I thought about a cycle stop valve but had already had the tanks. The pressure has to drop either way with the tanks for the pump to kick on at 40psi but I had a 10pm pump before that filled them quick. I know that as you go deeper with pumps things change with flow. My old pump would not have worked.

 

[Reach4]

No it doesn’t drop down below cut in. When the switch cuts in it will push but if a couple of fixtures get turned on it seems to hang instead of pushing the psi up. It may hang at 40-42 psi depending on where it was at when the extra call for water started. I understand it’s not the worst thing but a shower flow at 50-60 psi is different than at 40 psi.

Ideal IMO.

Consider a shower head with a flow regulator. Neoperl is a big brand in flow regulators.

 

[Valveman]

Looking at the pump curve for a 3/4HP, 5GPM pump there is a big drop in pressure as the flow increases from 5 to just 7 GPM. You are basically running out of pump at 6-7 GPM. I agree with Reach this is ideal for having the smallest pump possible to do the job, and making it have long run times so it will last. However, it is not ideal if you want good strong constant pressure and the ability to use as much water as you want.

Sure, the pressure has to drop either way, big tank or small tank/CSV. But with the small tank that happens before you get the shower temp adjusted and you never see it. With 20 gallons is two 44 gallon tanks the pressure in a 2.5 GPM shower will continue to decrease from 60 all the way down to 40 for 8 minutes before the pump starts and the pressure increases. That way you only get good pressure for the last 2 minutes of a 10 minute shower, or never in a 5 minute shower. With the CSV/small tank the pressure is strong and constant before you get in the shower, and will stay that way if you shower for a month.

The CSV basically lets you use as large a pump as you want, have strong constant pressure with as many fixtures open as you need, while not letting the pump cycle itself to death, even when using a small pressure tank.

 

[Charles McWilliams]

I use a Gould J5, 220 VAC, 1/2 hp, shallow well, single pipe. I have available a J10, 1.0 hp, 220 VAC. Is there any reason not to?

 

[Ron]

Sounds like you’re in a tough spot! If you’re constantly running low on water when you’ve got multiple things going, it definitely makes sense to consider a bigger pump. A 7 gpm pump would help with your demand, especially with all those appliances running at once. It’s a big investment, so it’s smart to get it right. Definitely bring it up with your well installer; they should be able to help you out.

 

[Reach4]

I use a Gould J5, 220 VAC, 1/2 hp, shallow well, single pipe. I have available a J10, 1.0 hp, 220 VAC. Is there any reason not to?

One reason would be that the existing pump is up to the job.

Why are you considering the change?